LIBRARY 

OF   THE 

UNIVERSITY  OF  CALIFORNIA. 

Class 


WORKS  OF  G.  C.  WHIPPLE 

PUBLISHED  BY 

JOHN   WILEY  &  SONS. 


The  Microscopy  of  Drinking-water. 

Second  edition,  revised.  8vo,  xii  +  338  pages, 
figures  in  the  text  and  19  full-page  half-tones. 
Cloth,  $3.50, 

The  Value  of  Pure  Water. 

Large  i2mo,  viii  -f  84  pages.    Cloth,  $1.00. 


THE 


Value  of  Pure  Water 


BY 

GEORGE    C.    WHIPPLE 


"  The  cost  of  a  thing  is  the  amount  of  what  I  will  call 
life  which  is  required  to  be  exchanged  for  it." — THOREAU 


FIRST    EDITION 
FIRST   THOUSAND 


NEW   YORK 

JOHN   WILEY   &   SONS 

LONDON:  CHAPMAN  &  HALL,  LIMITED 

1907 


Copyright,  1907 

BY 
GEORGE   C.  WHIPPLE 


ROBERT    DRUMMOND,    PRINTER,    NEW    YORK 


PREFACE 


"  THE  VALUE  OF  PURE  WATER"  appeared  originally 
in  a  collection  of  scientific  papers  entitled  "Biological 
Studies  by  the  Pupils  of  William  Thompson  Sedgwick." 
It  has  attracted  an  unexpected,  and  perhaps  undeserved, 
amount  of  attention,  which  goes  to  show  the  popular 
interest  in  the  subject.  The  constant  demand  upon  the 
author  for  copies  has  led  to  its  publication  in  the  pres- 
ent revised  form. 

The  author  wishes  to  disclaim  any  great  degree  of 
accuracy  or  permanency  for  the  formulae  suggested  and 
to  warn  the  reader  against  a  too  definite  application  of 
them  in  particular  cases.  The  whole  study  is  intended 
merely  to  illustrate  a  fact  which  in  the  past  has  been 
too  little  appreciated,  namely,  that  an  impure  water- 
supply  affects  not  only  the  health  and  comfort  of  a 
community,  but  also  the  individual  pocketbooks  of  the 

people. 

iii 


iv  Preface 

The  financial  standard  is  certainly  not  the  highest 
one  for  judging  the  quality  of  a  water-supply  when  the 
public  health  is  concerned;  human  life  cannot  be  esti- 
mated in  gold  dollars,  and  the  smell  of  unsavory  water 
to  a  thirsty  man  cannot  be  reckoned  in  dimes;  never- 
theless, the  financial  basis  is  a  convenient  one,  and  one 
necessarily  involved  in  all  questions  which  relate  to 
public  utilities. 

To  the  original  paper  have  been  added  a  few  extracts 
from  a  recent  lecture  delivered  at  the  Brooklyn  Poly- 
technic Institute  on  the  Disadvantages  of  Hard  Water 
and  from  an  address  delivered  at  the  Annual  Confer- 
ence of  Sanitary  Officers  of  the  State  of  New  York  on 
the  Pollution  of  Streams  and  the  Natural  Agencies  of 
Purification.  i 

GEORGE  C.  WHIPPLE. 

NEW  YORK,  January,  1907. 


TABLE  OF  CONTENTS 


THE  VALUE  OP  PURE  WATER 

PAGB 

INTRODUCTION i 

PURE  AND  WHOLESOME  WATER 2 

SANITARY  QUALITIES 7 

ATTRACTIVENESS 16 

HARDNESS 24 

TEMPERATURE 28 

SUMMARY  OF  FORMULAE 30 

APPLICATION  OF  FORMULA 35 

Effect  of  Contamination 36 

Effect  of  Turbidity,  Color,  and  Odor 37 

Effect  of  Hardness 41 

BENEFITS  OF  FILTRATION 41 

Sanitary  Quality 42 

Physical  Quality 45 

Water-softening 47 

COST  OF  FILTRATION 48 

SUMMARY 50 

v 


vi  Table  of  Contents 


WHAT  IS  PURE  AND  WHOLESOME  WATER 

PAGE 

DIFFICULTY  IN  DEFINING 53 

EPITHETS  ESPECIALLY  APPLICABLE  TO  WATERS  IN  A  NAT- 
URAL STATE 55 

EPITHETS  APPLICABLE  TO  WATER   WITH   ARTIFICIAL   SUB- 
STANCES ADMIXED 56 

THE  DISADVANTAGES  OF  HARD  WATER 

HARD  WATERS 62 

USE  OF  HARD  WATER  IN  THE  HOUSEHOLD 63 

USE  OF  HARD  WATER  IN  THE  INDUSTRIES 68 

USE  OF  HARD  WATER  IN  STEAM-MAKING 70 

FINANCIAL  Loss  FROM  THE  USE  OF  HARD  BOILER  WATERS 74 


LIST  OF  TABLES 


TABLE  PAGE 

1.  Financial  Value  of  Human  Life 9 

2.  Effect  of  Filtration  on  Death-rates  at  Albany  and  Troy,  N.  Y.  10 

3.  Typhoid -fever  Death-rates  in  Cities   and   Towns   which    have 

Ground-water  Supplies 14 

4.  Typhoid-fever  Death-rates  in  Twelve  States 16 

5.  Relation   between    Hardness  of  Water   and   Amount  of  Soap 

Required  to  Soften  It 26 

6.  Average  Cost  of  Softening  Water  by  Soap 27 

7.  Depreciation  Due  to  Sanitary  Quality.  .  .  . 31 

8.  Depreciation  Due  to  Turbidity 32 

9.  Depreciation  Due  to  Color 33 

10.  Depreciation  Due  to  Hardness 34 

11.  Depreciation  Due  to  Odor 35 

12.  Depreciation  Due  to  Temperature 35 

13.  Examples  of  Waters  with  Different  Physical  Characteristics. .  38 

14.  Ordinary  Seasonal  Variation  in  the  Depreciation  of  Surface- 

water  Due  to  Changes  in  Turbidity,  Color,  and  Odor 40 

15.  Extreme  Case  of  Seasonal  Variation  in  the  Depreciation  of  a 

Surface-water  Due  Chiefly  to  Growths  of  Algae 40 

16.  Range  in  Depreciation  of  Water  Due  to  Hardness 41 

17.  Effect  of  Filtration  on  the  Attractiveness  of  Waters 46 

vii 


viii  List  of  Tables 


PAGE 


TABLE 

1 8.  Table  Showing  Number  of  Observers  who  Could  Detect  by 

Taste  the  Presence  of  Various  Salts  Dissolved  in  Distilled 
Water  in  Amounts  Equal  to  or  Larger  than  those  Indicated  66 

19.  Comparison  Showing  the  Effect  of  Water -softening  at  Seven- 

teen Stations  on  the  Chicago  &  Northwestern  Railroad. . .   75 

DIAGRAM 
Diagram  for  Calculating  the  Esthetic  Deficiency  of  Water 18 


I    UNIVERSITY    ) 


THE  VALUE  OF  PURE  WATER 


N  order  to  estimate  the  relative  value  of 
waters  which  differ  materially  in  quality, 
it  is  necessary  to  have  some  common  de- 
nominator. Nothing  better  for  this  pur- 
pose has  been  suggested  than  the  dollar,  which  in  this 
discussion  is  made  the  basis  of  computation.  By  ascer- 
taining what  different  characteristics  of  water  cost  the 
consumers,  and  by  finding  out  how  much  consumers 
are  willing  to  pay  to  avoid  using  waters  which  possess 
these  characteristics,  an  attempt  has  been  made  to 
secure  a  reasonable  basis  of  comparison.  The  results  of 
this  initial  study  are  here  presented.  They  must  not  be 
taken  too  seriously  at  present,  as  some  of  the  involved 
assumptions  have  not  been  established  beyond  doubt. 
With  the  accumulation  of  certain  data,  desirable  but 
not  as  yet  obtainable,  the  results  must  be  somewhat 


2  The  Value  of  Pure  Water 

modified.  Yet  the  general  conclusions  here  drawn  ought 
not  to  be  far  astray,  and,  from  a  study  of  the  best  data 
available,  the  writer  believes  that  they  err  on  the  side 
of  conservatism  rather  than  on  the  opposite  side.  The 
suggested  method  of  calculating  the  value  of  pure  water 
seems  to  be  one  capable  of  being  refined  to  such  a 
degree  that  its  results  will  be  of  great  practical  value. 
The  lines  along  which  the  accumulation  of  data  is 
necessary  in  order  to  render  the  method  reliable  will  be 
evident  from  a  perusal  of  the  text. 


Pure  and  Wholesome  Water 

To  define  the  meaning  of  the  expression  "pure  and 
wholesome  water,"  which  is  so  often  found  in  water- 
supply  contracts,  would  seem  to  be  an  easy  matter,  after 
all  the  study  that  has  been  given  to  the  subject  in  recent 
years;  but,  although  every  one  knows  in  a  general  way 
what  is  implied  by  this  expression,  yet  when  it  comes 
to  framing  a  definition  in  positive  scientific  terms,  the 
problem  is  not  as  easy  as  it  seems.  This  is  not  because 
the  chemist  and  the  biologist  do  not  know  what  pure 
water  is,  but  because  water  has  so  many  attributes  which 
have  to  be  taken  into  consideration,  and  because  these 
attributes  vary  in  importance  in  every  instance.  "  Pure 
and  wholesome  water"  is  not  a  substance  of  absolute 


Pure  and  Wholesome  Water  3 

quality.  Strictly  speaking,  pure  water  does  not  exist 
in  nature;  all  natural  waters  contain  substances  in 
solution  or  in  suspension;  and  in  proportion  as  these 
substances  are  present,  and  in  proportion  as  they  are 
objectionable  in  character,  the  water  is  impure.  Defini- 
tions of  pure  and  wholesome  water,  therefore,  generally 
state  what  foreign  substances  shall  not  be  present,  or  in 
what  amounts  they  are  permissible,  instead  of  defining 
the  positive  qualities  which  the  water  shall  possess. 

Unquestionably  the  term  ' c  pure  and  wholesome 
water,"  as  ordinarily  used,  relates  to  water  intended 
to  -be  used  for  drinking.  Such  a  water  must  be  free 
from  all  poisonous  substances,  as  the  salts  of  lead;  it 
must  be  free  from  bacteria  or  other  organisms  liable  to 
cause  disease,  such  as  the  bacilli  of  typhoid  fever  or 
dysentery;  it  must  also  be  free  from  bacteria  of  fecal 
origin,  such  at  B.  coli.  In  other  words,  the  water  must 
be  free  from  poisonous  substances,  from  infection,  and 
even  from  contamination.*  Besides  this,  it  must  be 
practically  clear,  colorless,  odorless,  and  reasonably  free 
from  objectionable  chemical  salts  in  solution  and  from 
microscopic  organisms  in  suspension.  Moreover,  it 
must  be  well  aerated.  Color,  turbidity,  odor,  dissolved 
salts,  etc.,  may  be  permissible  to  a  small  degree  without 

*  By  this  term  Is  meant  pollution  with  fecal  matter,  Con- 
tamination must  be  considered  as  potential  infection. 


4  The  Value  of  Pure  Water 

throwing  the  water  outside  of  the  definition  of  pure  and 
wholesome  waters.  In  these  minor  matters  local  stand- 
ards govern  up  to  a  certain  point,  and  it  is  in  regard  to 
them  that  differences  in  the  judgment  and  experience 
of  analysts  lead  to  diverse  classifications. 

When  it  comes  to  using  water  for  other  purposes  than 
for  drinking,  other  attributes  have  to  be  considered. 
Hardness  makes  a  water  troublesome  to  wash  with  and 
to  use  in  boilers;  iron  makes  trouble  in  the  laundry; 
chlorine  corrodes  pipes  and  makes  work  for  the  plumb- 
ers; the  presence  of  the  carbonates  and  sulphates  of 
lime  and  magnesia  affects  the  paper-maker,  the  brewer, 
the  tanner,  the  dyer,  the  bleacher;  soda  causes  a  loco- 
motive boiler  to  foam,  and  affects  the  use  of  the  water 
for  irrigation.  All  of  these  constituents,  and  others 
which  are  not  named,  have  to  be  taken  into  considera- 
tion in  connection  with  a  public  water-supply,  which 
may  be  put  to  any  of  these  uses. 

If  it  is  a  difficult  matter  to  define  a  pure  and  whole- 
some water  in  strict  scientific  terms,  it  is  still  more  dif- 
ficult to  compare  waters  which  differ  in  purity  on  any 
reasonable  basis;  and  yet  this  often  has  to  be  done. 
Given  two  water  sources  equally  available  to  a  city  for 
purposes  of  supply,  both  safe  to  drink,  but  one  high- 
colored  and  soft,  the  other  colorless  and  hard— which 
is  the  better  selection?  A  water-works  plant  is  to  be 


Pure  and  Wholesome  Water  5 

appraised:  structurally  the  system  is  a  good  one,  but 
the  quality  of  the  water  is  unsatisfactory  because  of 
its  excessive  color  or  turbidity — how  much  should  be 
deducted  from  the  value  of  the  works  because  of  the  bad 
quality  of  the  water?  The  water-works  owned  by  a 
private  company  are  to  be  purchased  by  the  city;  the 
city  has  a  high  typhoid  fever  death-rate,  due  unques- 
tionably to  the  water-supply — how  much  less  should  the 
city  pay  because  of  that  fact?  A  city  in  the  West  is 
using  turbid  river  water — how  much  can  it  afford  to 
pay  to  filter  it?  A  city  in  New  England  is  using  a  water 
so  heavily  laden  with  Anabaena  that  it  is  nauseous  to 
drink — how  much  can  the  city  afford  to  pay  to  pro- 
cure a  new  supply?  These  are  all  practical,  every-day 
questions  which  deserve  answers  based  on  scientific 
data. 

In  valuation  cases  where  the  quality  of  the  water- 
supply  has  been  unsatisfactory,  the  cost  of  filtration, 
or  other  appropriate  method  of  purification,  has  been 
sometimes  taken  as  a  measure  of  the  inferior  quality  of 
the  water,  and  this  amount  deducted  from  the  value 
of  the  works.  In  case  filtration  was  impractical,  or 
more  expensive  than  securing  a  supply  from  a  new 
source,  the  additional  cost  of  such  new  supply  has  been 
sometimes  taken  as  a  measure  of  the  inferior  quality 
of  the  water,  and  the  amount  deducted  from  the  value 


6  The  Value  of  Pure  Water 

of  the  works.  Both  of  these  methods  are  similar  in 
that  they  contemplate  the  substitution  of  a  satisfac- 
tory water  for  one  not  satisfactory. 

Another  method  of  measuring  the  depreciation  appli- 
cable to  a  water-works  plant  because  of  an  inferior 
quality  of  the  supply  would  be  to  ascertain  what  the 
use  of  the  impure  water  has  cost  the  consumers  com- 
pared with  what  a  pure  and  satisfactory  water  would 
have  cost  them.  This  method  has  not  been  used  in 
practice,  but  it  seems  to  be  a  reasonable  one,  and  one 
which  would  be  of  more  general  application  than  the 
preceding,  if  the  data  upon  which  it  is  based  could  be 
accurately  determined.  Unfortunately,  this  is  not  the 
case  in  most  instances,  but  by  the  use  of  certain  general- 
ized data  and  assumptions  results  may  be  secured  which 
are  of  considerable  use  in  comparing  the  value  of  waters 
different  in  quality. 

The  qualities  of  a  public  water-supply  which  most 
affect  the  ordinary  consumer  are: 

1.  Its  sanitary  quality;  that  is,  its  liability  of  infec- 
tion with  disease  germs  or  substances  deleterious   to 
health. 

2.  Its  general  attractiveness,  or  lack  of  attractiveness, 
as  a  drinking-water. 

3.  Its  hardness,  so  far  as  this  relates  to  the  use  of 
soap  in  the  household. 


Sanitary   Qualities  7 

4.  Its  temperature,  so  far  as  this  relates  to 
drinking. 

Characteristics  which  affect  industrial  uses  are  too 
much  a  matter  of  local  concern  to  be  taken  into  account 
in  a  general  discussion,  although  they  are  by  no  means 
of  small  account,  and  in  some  communities  their  im- 
portance might  control.  These  are  referred  to  on  a 
later  page.  The  qualities  selected  are  to  be  considered 
as  illustrative  of  the  method  rather  than  as  a  complete 
exposition  of  it. 


Sanitary  Qualities 

If  the  water  under  consideration  has  been  used  for  a 
considerable  time,  the  typhoid-fever  death-rate  of  the 
community  will  fairly  well  represent  the  sanitary  quality 
of  the  water-supply.  It  will  not  tell  the  whole  story, 
but  in  most  cases  it  will  not  lead  far  astray.  In  order 
to  reduce  this  to  a  financial  basis,  it  is  necessary  to 
make  several  assumptions. 

The  financial  value  of  a  human  life  is  generally  taken 
as  $5,000,  but  according  to  Leighton  *  it  varies  at 
different  ages  from  $1,000  to  $7,000,  as  shown  by  Table 

*  M.  O.  Leighton,  Popular  Science  Monthly,  January,  1902. 


8  The  Value  of  Pure  Water 

i.  It  so  happens  that  persons  are  most  susceptible  to 
typhoid  fever  near  the  age  when  their  life-value  is  con- 
sidered greatest.  By  combining  the  life- value  at  dif- 
ferent ages  with  the  age  distribution  of  persons  dying 
of  typhoid  fever,  the  resulting  average  value  of  persons 
dying  from  typhoid  fever  is  found  to  be  $4,635,  which 
is  very  close  to  the  figure  ordinarily  used. 

The  percentage  mortality  of  typhoid-fever  patients  is 
sometimes  stated  as  10  per  cent;  that  is,  ten  cases  for 
every  death.  Figures  of  this  character  are  most  often 
based  on  hospital  records,  and  mild  cases  do  not  gen- 
erally reach  the  hospitals.  Studies  of  recent  typhoid 
epidemics  indicate  that  15  to  18  cases  for  each  death 
would  be  nearer  the  truth.  The  expense  of  medical 
treatment,  nursing,  and  medicine,  the  loss  of  wages  for 
a  month  or  more,  together  with  other  attending  ex- 
penses and  inconveniences,  would  doubtless  aggregate 
at  least  $100  per  case,  or  $1,000  for  the  10  cases  corre- 
sponding to  one  death.  If  the  estimate  of  $100  *s  con- 
sidered too  large,  it  may  be  answered  that  the  excess 
is  more  than  offset  by  the  fact  that  there  are  more  often 
from  15  to  18  cases  for  each  death  than  there  are  10. 
It  may  be  fairly  assumed,  therefore,  that  $6,000  is  a 
very  moderate  estimate  of  the  financial  loss  to  the  com- 
munity from  typhoid  fever  for  each  death  from  that 
disease. 


Sanitary  Qualities 


TABLE  1. 


Age. 

Estimated  value 
of  human  life. 

Per  cent  of 
deaths  from 
typhoid  fever. 

Product  of  col- 
umns 2  and  3. 

0-  5  years  
5-10     "     

$1,500 
2,300 

*.o 

5.9 

7,510 
13,570 

10-15     "     

2,500 

7.2 

18,000 

15-20     "     
20-25     "     
25-30     "     

3,000 
5,000   - 
7,500 

13.1 
16.7 
13.2 

39,300 
83,500 
99,100 

30-35     "     

7,000 

9.9 

69,300 

35-40     "    
40-45     "     

6,000 
5,500 

8.0 
5.6 

48,000 
30,900 

45-50     "     

5,000 

4.0 

20,000 

50-55     "     
55-60     "    ..... 
60-65     "    
65-70     "    
70           " 

4,500 
4,500 
2,000 
1,000 
1  000 

3.3 
2.6 
2.1 
1.5 
1  9 

15,000 
11,700 
4,200 
1,500 
1  900 

Total 

100  00 

$463  480 

Average  value  of  life  of  persons  dying  from  typhoid  fever,  $4,635.,- 

Typhoid  fever  is  by  no  means  the  only  disease  trans- 
mitted by  contaminated  water.  Dysentery  and  various 
other  diarrheal  diseases  precede  it  or  follow  in  its  train, 
and  in  most  instances  these  are  probably  due  to  the 
same  general  sources  of  contamination  as  those  which 
caused  the  typhoid  fever,  although,  of  course,  to  dif- 
ferent specific  infections.  The  reduction  of  the  typhoid- 
fever  death-rate  following  the  substitution  of  a  pure 
water  for  a  contaminated  water  is  often  accompanied 
by  a  drop  in  the  death-rate  from  other  diseases.  Thus, 
if  the  five  years  before  and  after  filtered  water  was  intro- 


IO 


The  Value  of  Pure  Water 


TABLE  2. 

EFFECT  OF  FILTRATION  ON  DEATH-RATES  AT  ALBANY,  N.  Y.,  AND  A 
COMPARISON  WITH  TROY,  N.  Y.,  WHERE  THE  WATER  WAS  NOT 
FILTERED. 


Death-rates  per  100,000. 

1894-98, 
before  fil- 
tration at 

1900-04, 
after  fil- 
tration at 

Decrease. 

Per  cent 
reduction 
of  death- 
rates. 

Albany. 

Albany. 

ALBANY 


Typhoid  fever  
Diarrheal  diseases  

104 
125 

26 
53 

78 
72 

75 
57 

Children  under  5  years.. 

606 

309 

297 

49 

Total  deaths  

2,264 

1,868 

378 

17 

TROY 


Typhoid  fever  

57 

57 

0 

0 

Diarrheal  diseases  
Children  under  5  years.. 
Total  deaths  

116 
531 
2,157 

102 
435 

2,028 

14 
96 
129 

12 

18 
6 

Remark. — Filtered  water  was  introduced  into  Albany  in  1899. 
The  water-supply  of  Troy  has  remained  practically  unchanged. 


duced  into  Albany,  N.  Y.,  are  compared,  it  will  be  seen 
that  the  reductions  in  deaths  from  general  diarrheal  dis- 
eases and  the  deaths  of  children  under  five  years  of  age 
were  much  greater  than  in  the  case  of  typhoid  fever. 
There  was  also  a  reduction  in  malaria,  but  this  probably 
represents  faulty  diagnosis  of  typhoid- fever  cases  before 


Sanitary  Qualities  1 1 

the  introduction  of  filtered  water  rather  than  a  real  reduc- 
tion of  malaria.  That  the  reduction  of  infant  mortality 
and  deaths  from  diarrheal  diseases  was  not  due  to  other 
conditions  seems  probable,  from  the  fact  that  in  the 
neighboring  city  of  Troy,  where  the  water-supply  was 
not  changed,  there  was  no  such  diminution  during  the 
same  period. 

Hazen,  in  his  paper  on  "Purification  of  Water  in 
America,"  read  at  the  International  Engineering  Con- 
gress at  St.  Louis,  called  attention  to  this  same  fact, 
that  after  the  change  from  an  impure  to  a  pure  supply 
of  water  the  general  death-rate  of  certain  communities 
investigated  fell  by  an  amount  considerably  greater 
than  that  resulting  from  typhoid  fever  alone — indicat- 
ing either  that  certain  other  infectious  diseases  were 
reduced  more  than  typhoid  fever,  or  that  the  general 
health  tone  of  the  community  had  been  improved. 
Thus,  for  five  cities  where  the  water-supply  had  been 
radically  improved  he  found: 

Per  100,000. 

Reduction  in  total  death-rate  in  five  cities  with  the  introduc- 
tion of  a  pure  water-supply 440 

Normal  reduction  due  to  general  improved  sanitary  conditions, 
computed  from  average  of  cities  similarly  situated,  but 
with  no  radical  change  in  water-supply 137 

Difference,  being  decrease  in  death-rate  attributable  to  change 

in  water-supply. 303 

Of  this,  the  reduction  in  deaths  from  typhoid  fever  was 71 

Leaving  deaths  from  other  causes  attributable  to  change  in 

water-supply 232 


12  The  Value  of  Pure  Water 

From  these  facts  it  is  evident  that  to  place  the  finan- 
cial loss  to  a  community  as  $6,000  for  each  death  from 
typhoid  fever  due  to  the  public  water-supply  is  to  use 
too  low  a  figure.  It  probably  ought  to  be  several  times 
as  high;  but  recognizing  the  lower  financial  value  placed 
on  the  lives  of  infants,  and  the  less  serious  character 
of  the  other  diseases,  and  wishing  to  be  as  conservative 
as  possible,  for  the  reason  that  typhoid  fever  is  not 
entirely  a  water-borne  disease,  $10,000  per  typhoid 
death  has  been  used  in  the  calculation  which  fol- 
lows. 

Since  typhoid  fever  is  a  disease  which  may  be  trans- 
mitted in  other  ways  than  by  water  (as,  for  instance, 
by  milk,  raw  fruit,  shell-fish,  or  flies),  it  is  necessary  to 
allow  a  certain  death-rate  for  these  other  causes,  for 
even  in  a  city  where  the  water-supply  is  perfect  there 
may  be  still  some  typhoid  fever.  This  has  been  some- 
times called  "residual  typhoid."  To  establish  this 
residual,  or  "normal,"*  is  a  difficult  matter,  but  for 
purposes  of  calculation  we  may  assume  it  to  be  deter- 
mined and  represent  it  by  the  letter  N. 

If  we  assume  that  all  typhoid  fever  in  excess  of  N 
is  due  to  the  water-supply,  and  if  we  assume  that  the 
daily  consumption  of  water  is  100  gallons  per  capita, 

*  This  term  "  normal "  must  not  be  assumed  to  mean  necessary 
typhoid.  ^ 


Sanitary  Qualities  13 

then,  letting  T  equal  the  typhoid-fever  death-rate  per 
100,000, 

(T-N)  10,000= loss  to  the  community  in  dollars  for 

365  x  100  x  100,000  gallons  of  water,  or  D  =  - — 


where  D  stands  for  the  loss  in  dollars  per  million  gallons 
of  water  used. 

Suppose  the  average  typhoid-fever  death-rate  for  a 
community  which  has  a  somewhat  polluted  water-supply 
has  averaged  43  per  100,000  for  a  period  of  five  years, 
and  suppose  that  for  this  place  the  value  of  N  is  esti- 
mated as  15,  then 

D  =  2.75  (43  — 15 )  =  $76.72,  if  the  per-capita  consump- 
tion is  100  gallons.  If  the  consumption  per  capita  is 
115  gallons,  D  would  be  jf£  of  $76.72,  or  $66.71;  if  it 
were  63  gallons  per  capita,  then  D  would  equal  iff-  of 
$76.72,  or  $121.77. 

The  value  of  N  must  be  naturally  subject  to  local 
variation,  and  in  order  to  obtain  an  idea  as  to  its  prob- 
able value,  a  compilation  of  typhoid-fever  death-rates 
has  been  made  for  cities  and  towns  in  different  parts 
of  the  country  which  use  ground  waters  or  filtered 
waters — that  is,  waters  which  may  be  considered  as 
free  from  contamination. 

The  following  is  a  generalized  summary  of  them. 


The  Value  of  Pure  Water 


TABLE  3. 

TYPHOID-FEVER   DEATH-RATES    IN    CITIES   AND    TOWNS    WHICH    HAVE 
GROUND-WATER    SUPPLIES. 


State. 

Number  of 
cities  and  towns 
averaged. 

Number  cf 
years 
averaged. 

Average 
typhoid-fever 
death-rate 
per  100,000. 

Maine 

2 

5 

6   4 

Massachusetts 

23 

5 

15  8 

Conne  ticut. 

4 

5 

9  5 

New  York  

13 

5 

24.7 

New  Jersey  

10 

1 

20.5 

Pennsylvania  

5 

1 

31.8 

Ohio  

22 

5 

32.4 

There  is  reason  to  believe  that  the  higher  rates  given 
above  do  not  correctly  represent  the  situation,  because 
in  some  instances  the  ground-water  was  supplemented 
by  the  occasional  use  of  water  which  may  have  been 
polluted.  Proximity  to  a  large  city  where  the  water- 
supply  is  contaminated  was  also  responsible  for  some 
of  the  high  figures;  so  also  was  the  absence  of  sewerage 
systems.  Nevertheless,  there  seems  to  be  a  marked 
tendency  for  the  typhoid-fever  rates  to  increase  in  the 
United  States  from  north  toward  the  south  in  those 
places  where  the  water-supply  is  reasonably  safe.  There 
are  some  exceptions  to  the  increase  southward,  how- 
ever. Thus,  in  Camden,  N.  J.,  which  is  supplied  with 
a  pure  ground-water,  the  typhoid  rate  was  only  12  in 
1901  and  20  in  1902.  Washington  is  a  city  which  has 


Sanitary  Qualities  1 5 

a  large  amount  of  typhoid  fever  due  to  causes  other 
than  water.     Here  the  value  of  N  is  over  30. 

In  Fuertes'  book  on  Water  and  the  Public  Health  *  a 
diagram  is  given  showing  that  the  typhoid-fever  death- 
rates  in  cities  supplied  with  ground-water  vary  from  5 
to  32  per  100,000  in  America,  and  from  6  to  33  per  100,- 
ooo  in  Europe,  the  average  being  about  18  in  America 
and  19  in  Europe.  It  is  shown  also  that  the  death-rates 
from  cities  supplied  with  filtered  water  vary  from  4  to 
20  in  America,  and  from  4  to  20  in  Europe,  the  average 
being  12  in  both  cases.  Recent  American  data  for 
cities  supplied  with  filtered  water  show  that  the  rates 
are  somewhat  higher  than  these,  the  average  being 
somewhat  less  than  20. 

Taking  into  consideration  the  best  available  data,  it 
seems  reasonable  to  place  the  general  value  of  N  some- 
where between  10  and  25  per  100,000,  with  the  most 
probable  average  value  as  20,  which  figure  may  be  used 
in  the  equation  where  local  sanitary  conditions  are  un- 
known. The  value  of  N,  however,  should  be  varied 
where  there  is  reason  for  doing  so.  Where  the  sanitary 
conditions  are  good,  15  may  be  taken  as  a  fair  value.  In 
New  England  it  might  be  placed  lower  than  in  regions 
south  of  the  glacial  drift;  in  cities  near  the  seaboard, 

*  Water  and  the  Public  Health,  by  James  H.  Fuertes,  John 
Wiley  &  Sons,  New  York,  1901. 


1 6  The  Value  of  Pure  Water 

where  there  is  a  large  consumption  of  oysters  taken 
fresh  from  the  layings,  the  value  of  N  might  be  higher 
than  in  inland  cities,  where  the  oyster  consumption  is 
small  and  where  fattened  oysters  are  not  used  as  freely; 
in  cities  where  there  are  cesspools  but  no  sewers,  the 
value  of  N  would  naturally  be  higher  than  in  cities  well 
provided  with  sewers. 

It  may  be  reasonably  expected  that,  as  time  goes  on, 
the  value  of  N  will  gradually  fall,  because  of  a  general 
decrease  of  typhoid  fever  in  the  country  at  large,  and  a 
consequent  diminution  of  the  number  of  foci  of  infec- 
tion. Statistics  for  twelve  States,  including  all  the  New 
England  States,  New  York,  New  Jersey,  Maryland, 
California,  Minnesota,  and  Michigan,  show  that  during 
the  last  quarter  of  a  century  the  general  typhoid- fever 
death-rate  has  fallen  as  follows: 

TABLE  4. 


1880  , 

Average  typhoid- 
fever  death- 
rate  per 
100,000. 

55 

1885  

46 

1890 

36 

1895               

28 

1900               

23 

1905.. 

21 

Attractiveness 

The  analytical  determinations  which  relate  to  the  gen- 
eral attractiveness  of  a  water  are  those  of  taste,  odor, 


Attractiveness  1 7 

color,  turbidity,  and  sediment.  As  these  quantities  in- 
crease in  amount,  the  water  becomes  less  attractive  for 
drinking  purposes,  until  finally  a  point  is  reached  where 
people  refuse  to  drink  it.  In  order  to  use  these  results 
in  a  practical  way,  it  is  necessary  to  combine  them  so 
as  to  obtain  a  single  value  for  the  physical  character- 
istics or,  as  they  say  abroad,  for  the  "organoleptic" 
quality  of  the  water.  An  attempt  has  been  made  by 
the  author  to  obtain  what  may  be  termed  an  aesthetic 
rating  of  the  water,  and  the  result  is  shown  in  the 
diagram  on  page  18. 

This  diagram,  it  should  be  said,  is  based  almost  en- 
tirely upon  estimates  and  very  little  upon  statistical 
data.  It  rests  upon  the  assumption  that  people  differ 
in  their  sensibilities  or  their  aesthetic  feelings  as  to  the 
use  of  water.  Some  persons  are  much  more  fastidious 
than  others  in  regard  to  what  they  drink.  A  water 
which  would  be  shunned  by  one  person,  even  though 
he  were  thirsty,  might  be  taken  by  another  with  ap- 
parent relish.  As  a  rule,  people  are  more  fastidious 
about  the  odor  of  water  and  the  amount  of  coarse  sedi- 
ment which  it  contains  than  they  are  about  its  color 
and  turbidity.  This  is  perhaps  natural,  as  a  bad  odor 
suggests  decay,  and  decay  is  instinctively  repugnant. 
Often,  however,  people  do  not  discriminate  between 
odors  which  are  due  to  decomposition  and  those  which 


18 


The  Value  of  Pure  Water 


jwmsicr » 


?UI«J  « 


sjatnnsuoo  Suijoefqo  jo  ?uao  Jiad. 


Attractiveness  1 9 

are  not.  Habit  and  association  have  much  to  do  with 
a  person's  views  as  to  the  attractiveness  of  water.  In 
New  England,  where  the  clear  trout  brooks  run  with 
what  Thoreau  called  "meadow  tea,"  few  people  object 
to  a  moderate  amount  of  color,  while  they  do  object  to 
a  water  which  is  very  turbid.  In  the  Middle  West, 
where  all  the  streams  are  muddy,  it  is  the  unknown 
colored  waters  which  are  disliked.  People  who  are 
accustomed  to  well-water  object  to  both  color  and  tur- 
bidity. With  most  people  a  fine  turbidity,  such  as  is 
produced  by  minute  clay  particles,  is  less  a  subject  of 
complaint  than  an  equal  turbidity  produced  by  com- 
paratively coarse  sediment.  In  the  diagram  an  attempt 
has  been  made  to  reconcile  these  different  points  of 
view,  so  as  to  put  them,  as  well  as  may  be,  on  the  same 
footing.  In  this  connection  several  series  of  compari- 
sons were  made.*  Turbid  waters  were  viewed  by  a 
group  of  Western  people,  who  made  some  comparisons 
with  colored  and  turbid  waters,  while  colored  waters 
were  viewed  by  a  group  of  students  in  New  York,  and 
vice  versa. 

The    abscissae    of    the    diagram   represent  turbidity, 
color,  and  odor,  as  given  in  the  ordinary  water  analy- 


*  Acknowledgments  are  due  to  Mr.  J.  W.  Ellms,  of  Cincinnati, 
Ohio,  and  Mr.  Andrew  Mayer,  Jr.,  of  Brooklyn,  N.  Y. 


20  The  Value  of  Pure  Water 

sis.*  The  ordinates  represent  the  "  per  cent  of  objecting 
consumers."  By  this  is  meant  the  proportion  of  the 
water-takers  who  would  ordinarily  choose  not  to  drink 
the  water  because  of  the  quality  indicated  by  the  curve, 
or  who  would  buy  spring  water,  or  bottled  water,  rather 
than  use  the  public  supply,  if  they  could  afford  to  do  so. 
This  number  would  increase,  of  course,  as  the  general 
attractiveness  of  the  water  decreased.  From  the  curves 
one  may  calculate  what  may  be  called  the  cesthetic 
deficiency  of  the  water  by  adding  together  the  per  cents 
of  objecting  consumers  for  color,  turbidity,  and  odor. 
If  the  aesthetic  deficiency  equals  100,  it  indicates  that 
the  water  is  of  such  a  character  that  every  one  would 
object  to  it,  and  figures  in  excess  of  100  only  emphasize 
its  objectionable  character. 

It  will  be  seen  from  the  diagram  that  when  the  color 
of  water  is  less  than  20,  or  the  turbidity  less  than  5,  only 
one  person  in  ten  would  object  to  it,  but  when  the  tur- 
bidity or  color  is  100,  one-half  of  the  people  would  object 
to  it.  It  may  be  thought  that  this  proportion  is  too 
low,  but  it  must  be  remembered  that  colored  waters 
are  invariably  accompanied  by  a  vegetable  odor  and 
often  by  a  slight  turbidity,  and  that  it  is  the  sum  of  the 
several  quantities  which  determines  the  aesthetic  rating. 

*  See  "Report  of  Committee  on  Standard  Methods  of  Water 
Analysis,  American  Public  Health  Association,"  Supplement 
No.  i,  Journal  of  Infectious  Diseases,  May,  1905. 


Attractiveness  2 1 

Experience  has  shown  that  objection  to  color  varies 
directly  with  its  amount;  consequently  this  curve  has 

c 

been  plotted  from  the  equation,  pc=-~,   i.e.,  a  straight 

line,  where  pc  stands  for  the  per  cent  of  objecting  con- 
sumers, and  c  for  the  color. 

In  the  case  of  turbidity,  however,  small  amounts 
count  for  more,  relatively,  than  larger  amounts.  The 
equation  for  the  turbidity  curve  has  been  taken,  there- 
fore, as  pt=5^t,  where  t  stands  for  the  turbidity. 

With  odor,  however,  the  opposite  condition  prevails; 
faint  odors  count  for  little,  but  distinct  and  decided 
odors  cause  much  more  complaint.  Consequently,  the 
per  cent  of  objecting  consumers  has  been  made  to  vary 
as  the  square  of  the  intensity  of  the  odor  expressed 
according  to  the  standard  numerical  scale.  The  quality 
of  the  odor  makes  quite  as  much  difference  as  its  in- 
tensity, and  for  that  reason  three  curves  have  been 
plotted,  one  representing  vegetable  or  pondy  odors 
(Ov),  one  representing  odors  due  to  decomposition  (Od), 
and  one  representing  the  aromatic,  grassy  and  fishy 
odors  due  to  microscopic  organisms  (OJ.  These  curves 
are  plotted  from  the  following  equations; 

fc-50t 
#.=3.503, 


22  The  Value  of  Pure  Water 

in  which  00,  Od,  and  Ov  stand  for  the  intensity  of  the 
three  groups  of  odors  mentioned. 

These  curves  represent  somewhat  imperfectly  our  pres- 
ent ideas  as  to  the  relative  effects  of  color,  turbidity, 
and  odor;  and  on  further  study  they  are  likely  to  be 
considerably  modified. 

It  is  a  well-known  fact  that  in  cities  which  are  sup- 
plied with  water  which  is  not  attractive  for  drinking 
purposes,  large  quantities  of  spring  water  and  distilled 
water  are  sold,  and  that  consumers  go  to  much  expense 
in  the  purchase  of  house-filters  in  order  to  improve  the 
quality  of  the  water  furnished  by  the  city  mains.  It  is 
fair  to  assume  that  in  any  community  the  amount  of 
money  expended  for  bottled  water  and  house-filters 
will  vary  in  a  general  way,  according  to  the  attractive- 
ness of  the  water,  although  there  is  no  doubt  that  the 
presence  of  typhoid  fever  in  the  community,  or  the 
fear  that  the  water  is  contaminated,  will  greatly  in- 
crease the  use  of  auxiliary  supplies  for  drinking.  For 

•v 

purposes  of  calculation  it  may  be  assumed  that  the  dia- 
gram just  described  represents  this  tendency  to  use 
vended  waters,  and  that  each  "objecting  consumer" 
would  go  to  the  expense  of  buying  spring-water  or  put- 
ting in  a  house-filter,  if  he  could  afford  it.  It  may  be 
argued,  also,  that  the  poor  consumer  who  may  be  un- 


Attractiveness  23 

able  to  do  this  is  as  much  entitled  to  satisfactory  water 
as  is  the  well-to-do  consumer. 

From  a  study  of  price-lists  of  spring-waters  sold  in 
New  York  and  other  cities,  it  has  been  found  that  the 
ordinary  wholesale  price  of  spring-water  is  seldom  more 
than  10  cents  a  gallon.  In  some  places  it  is  as  low  as  i 
cent.  The  average  is  about  5  cents.  To  filter  water 
through  house-filters  costs  less,  but  generally  it  is  less 
satisfactory. 

As  a  convenient  figure  for  calculation,  and  as  a  most 
conservative  one  for  general  use,  a  cost  of  I  cent  per 
gallon  to  the  ordinary  consumer  for  an  auxiliary  supply 
of  drinking-water  (either  spring-water  or  well-filtered 
water)  has  been  taken.  In  cities  where  the  cost  of 
procuring  and  distributing  bottled  water  exceeds  i  cent 
per  gallon,  as  it  does  in  such  a  city  as  New  York  for 
example,  this  should  be  taken  into  account  in  making 
local  use  of  the  data.  For  the  illustrative  purposes  of 
the  present  study,  and  for  general  comparisons,  the 
figure  mentioned  will  serve  as  a  satisfactory  basis. 
The  average  person  drinks  about  1.5  quarts  of  liquid 
per  day,  of  which  one-half  may  be  assumed  to  be  water, 
the  rest  being  tea,  coffee,  etc.  Therefore  one-fifth  cent 
per  capita  daily  may  be  taken  as  a  reasonable  figure  for 
the  cost  of  an  auxiliary  supply.  If  the  entire  popula- 
tion used  such  a  supply,  and  if  the  daily  consumption 


24  The  Value  of  Pure  Water 

of  the  public  water-supply  were  100  gallons  per  capita, 
then  one-fifth  cent  per  hundred  gallons,  or  $20  per 
million  gallons,  would  represent  the  loss  to  the  con- 
sumers due  to  an  imperfect  water-supply  which  had  an 
aesthetic  deficiency  of  100.  If  the  aesthetic  deficiency  f 
were  less  than  100,  say  37,  then  the  loss  to  the  consumer 
would  be  T¥?F  of  $20,  or  $7.40  per  million  gallons.  In 
other  words,  the  figure  for  the  aesthetic  deficiency 
divided  by  5  gives  the  financial  depreciation  of 
the  water-supply  in  dollars  per  million  gallons,  or 


100 

Example:  Suppose  the  turbidity  of  a  water  is  3,  its 
color  65,  and  its  odor  2/  (that  is,  faintly  fishy),  because 
of  the  presence  of  microscopic  organisms;  then  D  = 

2QI2'i32  +  20  =  $12.80;    that    is,    the    depreciation    of 
100 

the  water,  because  of  its  unsatisfactory  physical  quali- 
ties, amounts  to  $12.80  per  million  gallons. 


Hardness 

The  point  at  which  a  water  becomes  objectionably 
hard  has  never  been  exactly  defined.  Standards  of 
hardness  vary  in  different  parts  of  the  country.  The 
ordinary  person  washing  his  hands  considers  the  water 


Hardness  25 

soft  if  the  soap  will  quickly  produce  a  suds  without 
curdling.  A  hardness  of  10  parts  per  million  is  prac- 
tically unnoticeable,  and  it  requires  a  hardness  of  20 
or  30  parts  per  million  to  produce  "curdling."  Waters 
which  have  a  hardness  below  25  parts  per  million  sel- 
dom cause  much  complaint,  but  when  the  hardness 
rises  above  50  the  water  is  well  entitled  to  the  ap- 
pellation "hard,"  and  above  100  it  may  be  called 
very  hard.  In  some  parts  of  the  country  hardnesses 
of  200  or  300  are  observed;  these  may  be  termed 
"excessive." 

In  1903  a  number  of  experiments  were  made  by  the 
author  to  determine  the  effect  of  various  degrees  of 
hardness  on  the  amount  of  soap  produced  in  washing  the 
hands,  in  bathing,  and  in  general  household  uses.  These 
showed  that  the  hardness  of  the  water  had  a  substantial 
effect  on  the  use  of  soap.  Tests  were  also  made  with 
eight  of  the  common  soaps  and  washing  powders  on  the 
market,  to  determine  how  much  of  the  average  soap 
used  in  a  household  it  would  take  to  completely  soften 
waters  of  different  degrees  of  hardness.  Comparative 
figures  were  also  obtained  for  the  standard  Castile  soap 
commonly  used  in  the  laboratory  making  the  soap  test 
for  hardness.  The  results  of  these  experiments  are 
given  in  Table  5. 


26  The  Value  of  Pure  Water 

TABLE  5. 

TABLE  SHOWING  THE  RELATION  BETWEEN  THE  HARDNESS  OF  WATER 
AND  THE  AMOUNT  OF  SOAP  REQUIRED  TO  SOFTEN  IT. 


2  . 

u 

*  &<s 

^g10 

III 

dumber  of  gallons  of  water  softened  by  one  pound  of 

i 

P« 

i 

'                                *~N 

11 

d  1 

o-Sc 

•s|| 

1* 

a 

•*i 

-c 
c 

C3 

*3 

1                ^f 

a 

>-  «.2  ^ 

03  02 

i 

•«  c 

.2 

1 

02 

3 

0) 

.B 

JS 

•SI  . 

t?  c8  ft 

d,^  S^J 

T3  <3 

'sill 

3   02    02   £ 

|^P 

|| 

g 

ll 

1 

a 

"o 

1 

""& 

III 

Ills 

n 

2 

02 

M 

PQ 

GQ 

ffl 

O 

ft 

^ 

0 

< 

20 

2.1 

1.11 

409 

196 

138 

102 

143 

~65 

167 

187 

225 

167 

25 

2.4 

1.27 

358 

174 

121 

90 

125 

145 

147 

164 

206 

147 

40 

3.6 

1.91 

238 

115 

80 

£9 

83 

96 

98 

109 

137 

97 

50 

4.3 

2.28 

200 

96 

67 

50 

70 

81 

82 

92 

115 

82 

75 

6.1 

3.24 

140 

67 

47 

35 

49 

57 

58 

64 

80 

57 

80 

6.4 

3.49 

130 

70 

44 

33 

45 

52 

53 

60 

75 

54 

100 

7.8 

4.13 

110 

53 

37 

27 

38 

44 

45 

50 

63 

45 

125 

9.5 

5.04 

90 

43 

30 

25 

31 

36 

37 

41 

52 

37 

150 

11.1 

5.89 

77 

37 

26 

19 

27 

31 

32 

35 

44 

31 

175 

12.7 

6.74 

67 

32 

23 

17 

23 

27 

28 

31 

38 

27 

200 

14.3 

7.59 

60 

29 

20 

15 

21 

24 

25 

27 

34 

24 

It  was  found  that  one  pound  of  the  average  soap 
would  soften  167  gallons  of  water  which  had  a  hardness 
of  20  parts  per  million.  This  is  equivalent  to  about 
three  tons  of  soap  per  million  gallons.  It  was  also 
found  that  for  every  increase  of  one  part  per  million  of 
hardness  the  cost  of  soap  increased  about  $10  per 
million  gallons  of  water  completely  softened.  The  fol- 
lowing table  shows  the  way  in  which  this  amount  was 
calculated. 


Hardness 


27 


TABLE  6. 
TABLE  SHOWING  THE  AVERAGE  COST  OF  SOFTENING  WATER  BY  SOAP. 


cs  a 

ffi 


fli    l 


in  h 
above 

ermil 


•Sii 


l^FJ 

•~  a  $  S  wg  c73 
11-3°  Jill 


20 

25 

40 

50 

75 

80 

100 

125 

150- 

175 

200 


167 
147 
97 
82 
57 
54 
45 
37 
31 
27 
24 


5,990 
6,810 
10,300 
12,200 
17,500 
18,500 
22,200 
27,100 
32,200 
37,100 
41,700 

Average 


5 

20 

30 

55 

60 

80 

105 

130 

155 

180 


820 

4,310 

6,210 

11,510 

12,510 

16,210 

21,110 

26,210 

31,110 

35,710 


164 
215 
207 
209 
209 
203 
200 
202 
201 


$  8.20 
10.75 
10.35 
10.45 
10.45 
10.15 
10.00 
10.10 
10.05 
9.95- 


201 


$10.05 


All  of  the  water  used  by  a  community  is  not  com- 
pletely softened.  The  number  of  gallons  per  capita 
per  day  completely  softened  has  been  estimated  by 
different  authorities  all  the  way  from  i  to  10.  It  will 
certainly  be  a  conservative  estimate  to  assume  that  one 
gallon  per  capita  is  thus  softened.  ^On  this  basis  the 

depreciation   of   water,    on   account   of    its    hardness, 

ft 
is  D  =— ,  in  which  H  equals  the  hardness  of  the  water 

in  parts  per  million,  and  D  the  depreciation  in  dollars 
per  million  gallons. 


28  The  Value  of  Pure  Water 

Example:  Assume  the  total  hardness  of  a  water  to  be 

79  parts  per  million;  then  Z>=—  =$7.90  per  million 

gallons. 

This  takes  into  account  only  the  cost  of  soap  used  for 
domestic  purposes,  and  does  not  include  the  incidental 
losses  and  inconveniences  attendant  upon  the  use  of 
hard  water  in  the  household.  These,  if  they  could  be 
expressed  in  terms  of  dollars  and  cents,  would  probably 
more  than  equal  the  cost  of  soap;  therefore  the  above 
figures  err  on  the  side  of  conservatism. 

Temperature 

Every  one  knows  that  warm  water  is  unpalatable. 
When  the  temperature  rises  above  60°  F.,  people  do  not 
like  to  drink  it  without  cooling.  The  relation  between 
the  temperature  of  the  water  and  the  per  cent  of  object- 
ing consumers  may  be  represented  by  a  curve  based  on 

the  equation  p= ,  in  which  p  equals  the  per 

cent  of  objecting  consumers,  and  d  equals  the  tempera- 
ture of  the  water  in  Fahrenheit  degrees.  According  to 
this  formula,  no  one  would  object  to  drink  a  water  which 
had  a  temperature  of  45°,  half  the  people  would  object 
at  66°,  and  all  would  object  at  75°.  If  it  is  assumed 
that  it  takes  one-half  pound  of  ice  per  capita  daily  to 


Temperature  29 

cool  the  water  used  for  drinking  during  four  months  in 
the  year,  and  that  ice  costs  30  cents  per  100  pounds, 
then  the  depreciation  due  to  temperature  would  be 
equivalent  to  $5  per  million  gallons  of  public  supply 
for  100  per  cent  of  objecting  consumers,  assuming  the 
per-capita  consumption  to  be  100  gallons  daily,  or 

p  (d-At\2 

D  =  -J—  x$5  = T? —  in  dollars  per  million  gallons,  in 

which  d=the  average  temperature  during  the  four 
warmest  months  of  the  year.  This  may  be  considered 
as  the  depreciation  due  to  temperature.  The  tem- 
perature of  ground-water  seldom  rises  above  60°  in 
the  house-taps  even  in  summer,  and  in  cities  supplied 
with  ground-water  a  large  proportion  of  the  consumers 
do  not  use  ice.  Surface-waters,  on  the  other  hand,  in 
the  latitude  of  New  York,  generally  maintain  a  tem- 
perature of  60°  or  more  at  the  house-taps  for  at 
least  four  months  of  the  year.  The  temperature  factor 
is  an  important  one  in  many  cases,  but  it  need  not 
be  used  except  when  comparing  surface-waters  with 
ground-waters. 

In  a  similar  way  it  might  be  possible  to  calculate  the 
reduced  value  of  a  water  due  to  other  objectionable 
characteristics,  such  as  the  presence  of  large  amounts 
of  iron  or  chlorine.  Except  in  special  cases,  these 
would  not  be  as  important  as  the  more  obvious  quali- 


30  The  Value  of  Pure  Water 

ties    above    described,   and    they    need    not    be    con 
sidered  in  this  discussion. 


Summary  of  Principal  Formulae 

Depreciation  due  to  sanitary  quality  : 


Depreciation  due  to  physical  characteristics  : 

2.  D^+fi+p. 

100 


Depreciation  due  to  hardness  : 

-  "4 

Depreciation  due  to  temperature  : 
4.  D-(d~\  in  which 


£>=the  depreciation  in  dollars  per  million  gallons; 

T  —  typhoid-fever  death-rate  per  100,000; 

N=  typhoid-fever   death-rate   assumed    to   be    due   to 

causes   other   than  water,   and  which  may  be 

ordinarily  taken  as  20  per  100,000; 


Summary  of  Principal  Formulae         3 1 


TABLE  7. 
DEPRECIATION  DUE  TO  SANITARY  QUALITY. 

Values  of  D  for  different  values  of  T-N  in  the  formula  D=2.75(T-N). 
Dollars  per  million  gallons. 


T-N 

0 

1 

2 

3 

4 

5 

6 

7 

o 

9 

0 
10 
20 
30 
40 

0.00 
27.50 
55.00 
82.50 
110.00 

2.75 
30.25 
57.75 
85.25 
112.75 

5.50 
33.00 
60.50 
88.00 
115.50 

8.25 
35.75 
63.25 
90.75 
118.25 

11.00 
38.50 
66.00 
93.50 
121.00 

13.75 
41.25 
68.75 
96.25 
123.75 

16.50 
44.00 
71.50 
99.00 
126.50 

19.25 
46.75 
74.25 
101.75 
129.25 

22.00 
49.50 
77.00 
104.50 
132.00 

24.75 
52.25 
79.75 
107.25 
134.75 

50 
60 
70 
80 
90 

137.50 
165.00 
192.50 
220.00 
247.50 

140.25 
167.55 
195.25 
222.75 
250.25 

143.00 
170.50 
198.00 
225  .  50 
253.00 

145.75 
173.25 
200.75 
228.25 
255.75 

148.50 
176.00 
203.50 
231.00 
258.50 

151.25 
178.75 
216.25 
233.75 
261.25 

154.00 
181.50 
209.00 
236.50 
264.00 

156.75 
184.25 
211.75 
239.25 
266.75 

159.50 
187.00 
214.50 
242.00 
269.50 

162.25 
189.75 
217.25 
244.75 
272.25 

100 
110 
120 
130 
140 

275.00 
302.50 
330.00 
357.50 
385.00 

277.75 
305.25 
332.75 
360.25 
387.75 

280.50 
308.00 
335.50 
363.00 
390.50 

283.25 
310.75 
338.25 
365.75 
393.25 

286.00 
313.50 
341.00 
368.50 
396.00 

288.75 
316.25 
343.75 
371.25 
398.75 

291.50 
319.00 
346.50 
374.00 
401  .  50 

294.25 
321.75 
349  .  25 
376.75 
404.25 

297.00 
324.50 
352.00 
379.50 
407.00 

299.75 
327.25 
354.75 
382.25 
409.75 

150 

412.50 

415.25 

418.00 

420.75 

423.50 

426.25 

429.00 

431.75 

434.50 

437.25 

pc=per  cent  of  consumers  who  object  to  the  color  of 

the  water; 
p,  =per  cent  of  consumers  who  object  to  the  turbidity 

of  the  water; 
P0  =  per  cent  of  consumers  who  object  to  the  odor  of 

the  water; 
c=  color  reading; 
t=  turbidity  reading; 
Ov  =  odors  due  to  vegetable  matter,  expressed  according 

to  standard  numerical  scale; 
Od=  odors  due  to  decomposition,  expressed  according 

to  standard  numerical  scale; 


The  Value  of  Pure  Water 


TABLE  8. 

DEPRECIATION  DUE  TO  TURBIDITY. 
Values  of  D  for  different  values  of  i  in  the  formula  D  = 
Dollars  per  million  gallons. 


20X5VT 
100       ' 


l.§ 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

0 

1.00 

1.41 

1.73 

2.00 

2.23 

2.44 

2.64 

2.82 

3.00 

10 

'slie' 

3.31 

3.46 

3.60 

3.74 

3.87 

4.00 

4.12 

4.24 

4.35 

20 

4.47 

4.58 

4.69 

4.79 

4.89 

5.00 

5.09 

5.19 

5.29 

5.38 

30 

5.47 

5.56 

5.65 

5.74 

5.83 

5.91 

6.00 

6.08 

6.16 

6.18 

40 

6.32 

6.40 

6.48 

6.55 

6.63 

6.70 

6.78 

6.85 

6.92 

7.00 

50 

7.07 

7.14 

7.21 

7.28 

7.34 

7.41 

7.48 

7.54 

7.61 

7.68 

60 

7.74 

7.81 

7.87 

7.93 

8.00 

8.06 

8.12 

8.18 

8.24 

8.30 

70 

8.36 

8.42 

8.48 

8.54 

8.60 

8.66 

8.71 

8.77 

8.83 

8.88 

80 

8.94 

9.00 

9.05 

9.11 

9.16 

9.21 

9.27 

9.34 

9.36 

9.43 

90 

9.48 

9.53 

9.59 

9.64 

9.69 

9.74 

9.78 

9.84 

9.89 

9.94 

It 

0 

10 

20 

30 

40 

50 

60 

70 

80 

90 

H 

100 

10.00 

10.48 

10.95 

11.40 

11.83 

12.24 

12.64 

13.03 

13.41 

13.78 

200 

14.14 

14.49 

14.83 

15.16 

15.49 

15.81 

16.12 

16.43 

16.73 

17.03 

300 

17.32 

17.60 

17.88 

18.16 

18.43 

18.70 

18.97 

19.23 

19.49 

19.74 

400 

20.00 

20.24 

20.49 

20.73 

20.97 

21.23 

21.44 

21.67 

21.90 

22.13 

500 

22.36 

22.58 

22.80 

23.02 

23.23 

23.45 

23.66 

23.87 

24.08 

24.28 

600 

24.49 

24.69 

24.89 

25.09 

25.29 

25.49 

25.69 

25.88 

26.07 

26.26 

700 

26.45 

26.64 

26.83 

27.01 

27.20 

27.38 

27.56 

27.74 

27.92 

28.10 

800 

28.28 

28.44 

28.63 

28.80 

28.98 

29.15 

29.32 

29.49 

29.62 

29.83 

900 

30.00 

30.16 

30.33 

30.49 

30.69 

30.82 

30.98 

31.14 

31.30 

31.46 

1000 

31.62 

00= odors   due    to   microscopic   organisms,   expressed 

according  to  standard  numerical  scale; 
H=  Hardness  of  water  in  parts  per  million; 
d  =  average  temperature  of  water  during  four  warmest 
months. 


Summary  of  Principal  Formulae         33 


TABLE  9. 
DEPRECIATION  DUE  TO  COLOR. 

Values  of  D  for  different  values  of  c  in  the  formula  D  •- 
Dollars  per  million  gallons. 


20X| 

100  • 


Color 

0 

l 

2 

3 

4 

5 

6 

7 

8 

9 

0 

0.1 

0.2 

0.3 

0.4 

0.5 

0.6 

0.7 

0.8 

0.9 

10 

i.o 

1.1 

1.2 

1.3 

1.4 

1.5 

1.6 

1.7 

1.8 

1.9 

20 

2.0 

2.1 

2.2 

2.3 

2.4 

2.5 

2.6 

2.7 

2.8 

2.9 

30 

3.0 

3.1 

3.2 

3.3 

3.4 

3.5 

3.6 

3.7 

3.8 

3.9 

40 

4.0 

4.1 

4.2 

4.3 

4.4 

4.5 

4.6 

4.7 

4.8 

4.9 

50 

5.0 

5.1 

5.2 

5.3 

5.4 

5.5 

5.6 

5.7 

5.8 

5.9 

60 

6.0 

6.1 

6.2 

6.3 

6.4 

6.5 

6.6 

6.7 

6.8 

6.9 

70 

7.0 

7.1 

7.2 

7.3 

7.4 

7.5 

7.6 

7.7 

7.8 

7.9 

80 

8.0 

8.1 

8.2 

8.3 

8.4 

8.5 

8.6 

8.7 

8.8 

8.9 

90 

9.0 

9.1 

9.2 

9.3 

9.4 

9.5 

9.6 

9.7 

9.8 

9.9 

100 

10.0 

10.1 

10.2 

10.3 

10.4 

10.5 

10.6 

10.7 

10.8 

10.9 

110 

11.0 

11.1 

11.2 

11.3 

11.4 

11.5 

11.6 

11.7 

11.8 

11.9 

120 

12.0 

12.1 

12.2 

12.3 

12.4 

12.5 

12:6 

12.7 

12.8 

12.9 

130 

13.0 

13.1 

13.2 

3.3 

13.4 

13.5 

13.6 

13.7 

13.8 

13.9 

140 

14.0 

14.1 

14.2 

14.3 

14.4 

14.5 

14.6 

14.7 

14.8 

14.9 

150 

15.0 

15. 

15.2 

15.3 

15.4 

15.5 

15.6 

15.7 

15.8 

15.9 

160 

16.0 

16. 

16.2 

16.3 

16.4 

16.5 

16.6 

16.7 

16.8 

16.9 

170 

17.0 

17. 

17.2 

17.3 

17.4 

17.5 

17.6 

17.7 

17.8 

17.9 

180 

18.0 

18.1 

18.2 

18.3 

18.4 

18.5 

18.6 

18.7 

18.8 

18.9 

190 

19.0 

19.1 

19.2 

19.3 

19.4 

19.5 

19.6 

19.7 

19.8 

19.9 

200 

20.0 

34 


The  Value  of  Pure  Water 


TABLE  10. 


DEPRECIATION    DUE   TO    HARDNESS. 

TT 

Values  of  D  for  different  values  of  H  in  the  formula  D  = — . 
Dollars  per  million  gallons. 


ji 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

K 

0 

0.10 

0.20 

0.30 

0.40 

0.50 

0.60 

0.70 

0.80 

0.90 

10 

1  00 

1.10 

1.20 

1.30 

1.40 

1.50 

1.60 

1.70 

1.80 

1.90 

20 

2^00 

2.10 

2.20 

2.30 

2.40 

2.50 

2.60 

2.70 

2.80 

2.90 

30 

3.00 

3.10 

3.20 

3.30 

3.40 

3.50 

3.60 

3.70 

3.80 

3.90 

40 

4.00 

4.10 

4.20 

4.30 

4.40 

4.50 

4.60 

4.70 

4.80 

4.90 

50 

5  00 

5.10 

5.20 

5.30 

5.40 

5.50 

6.60 

6.70 

5.80 

5.90 

60 

6.00 

6.10 

6.20 

6.30 

6.40 

6.50 

6.60 

6.70 

6.80 

6.90 

70 

7.00 

7.10 

7.20 

7.30 

7.40 

7.50 

7.60 

7.70 

7.80 

7.90 

80 

8.00 

8.10 

8.20 

8.30 

8.40 

8.50 

8.60 

8.70 

8.80 

8.90 

90 

9.00 

9.10 

9.20 

9.30 

9.40 

9.50 

9.60 

9.70 

9.80 

9.90 

"S  $ 

0 

10 

20 

30 

40 

50 

60 

70 

80 

90 

100 
200 

10.00 
20,00 

11.00 
21.00 

12.00 
22.00 

13.00 
23.00 

14.00 
24.00 

15.00 
25.00 

16.00 
26.00 

17.00 
27.00 

18.00 
28.00 

19.00 
29.00 

300 

30.00 

31.00 

32.00 

33.00 

34.00 

35.00 

36.00 

37.00 

38.00 

39.00 

400 

40.00 

41.00 

42.00 

43.00 

44.00 

45.00 

46.00 

47.00 

48.00 

49.00 

500 

50.00 

51.00 

52.00 

53.00 

54.00 

55.00 

56.00 

57.00 

58.00 

59.00 

600 

60.00 

61.00 

62.00 

63.00 

64.00 

65.00 

66.00 

67.00 

68.00 

69.00 

700 

70.00 

71.00 

72.00 

73.00 

74.00 

75.00 

76.00 

77.00 

78.00 

79.00 

800 

80.00 

81.00 

82.00 

83.00 

84.00 

85.00 

86.00 

87.00 

88.00 

89.00 

900 

90.00 

91.00 

92.00 

93.00 

94.00 

95.00 

96.00 

97.00 

98.00 

99.00 

1000 

100.00 

Application  of  the  Formulas  35 


TABLE  11. 
DEPRECIATION  DUE  TO  ODOR. 

Values  of  D  for  different  values  of  Ov,  Od,  and  00  in  the  formula 
20(2<V+3.50d2+5OQ2 

100 
Dollars  per  million  gallons. 


D 


Odor. 

Vegetable 
odor 
(Ov). 

Odor  of 
decomposition 
(Od). 

Odor  due  to 
organisms 
(00). 

o       .  .  . 

None 

0.0 

0.0 

0  0 

1  

2  

Very  faint 
Faint 

0.4 
1.6 

0.7 

2.8 

1.0 
4.0 

3  

Distinct 

3.6 

6.3 

9.0 

4  

Decided 

6.4 

11.2 

16.0 

5 

Strong 

10  0 

17  5 

25  0 

TABLE  12. 

DEPRECIATION    DUE   TO    TEMPERATURE. 

Values  of  D  for  different  values  of  d  in  the  equation  D 
Dollars  per  million  gallons. 


loO 


Tem- 

pera- 

0 

l 

2 

3 

4 

5 

6 

7 

8 

9 

ture. 

40 

0  02 

0  01 

0  09 

50 

0.13 

0.20 

0.27 

0.35 

0.45 

0.56 

0.68 

0.80 

0.94 

1.09 

60 

0.25 

1.25 

1.61 

1.80 

2.01 

2.22 

2.45 

2.69 

2.94 

3.20 

70 

3.45 

3.75 

4.05 

4.35 

4.68 

5.00 

5.34 

5.69 

6.05 

6.43 

80 

6.81 

7.20 

7.60 

8.03 

8.45 

8.90 

9.35 

9.80 

10.28 

10.75 

Application  of  the  Formulae 

It  now  remains  to  apply  the  principles  above  set 
forth  to  actual  cases  and  see  to  what  conclusions  they 
lead. 


36  The  Value  of  Pure  Water 

EFFECT  OF  CONTAMINATION 

The  average  death-rate  from  typhoid  fever  in  Ameri- 
can cities  which  have  more  than  30,000  inhabitants  is 
about  35  per  100,000.  Applying  formula  (i),  and 
assuming  a  value  of  20  for  N,  then 

#=2.75(35 -20)  =$41.25; 

that  is,  the  average  depreciation  of  the  water-supplies 
of  our  American  cities,  taken  as  a  whole,  is  $41.25  per 
million  gallons,  because  of  their  unsanitary  quality,  or 
about  $15,000  per  annum  for  each  million  gallons  a 
day  of  supply. 

The  above  figure  takes  into  account  both  good  and 
bad  supplies.  The  average  typhoid-fever  death-rate 
in  those  cities  which  have  reasonably  good  water-sup- 
plies may  be  taken  in  round  numbers  as  about  20,  while 
in  those  cities  which  have  supplies  more  or  less  con- 
taminated it  varies  from  this  up  to  40  or  60.  In  some 
of  the  worst  cases  it  is  more  than  100  per  100,000.  In 
Pittsburg,  for  example,  the  typhoid  death-rate  for  sev- 
eral years  has  averaged  120.  Here,  according  to  for- 
mula (i),  D  =2.75(120-20)  =  $275  per  million  gallons. 
This  is  figured,  however,  on  a  per-capita  water  consump- 
tion of  100  gallons  a  day.  The  actual  consumption  is 
about  250  gallons  per  capita  per  day;  hence  D  should 
be  taken  as  ££g-  of  $275,  or  $110  per  million  gallons. 


Application  of  the  Formulae  37 

Each  million  gallons  of  polluted  Allegheny  River  water 
pumped  to  Pittsburg  has  therefore  reduced  the  vital 
assets  of  the  community  by  $110.  This,  for  a  popula- 
tion of  350,000,  amounts  to  $3,850,000  per  year — a  sum 
enormously  greater  than  the  annual  cost  of  making  the 
water  pure. 

Classifying  water-supplies  according  to  their  source, 
the  following  will  give  a  general  idea  as  to  the  deprecia- 
tion of  various  types  of  water  from  the  sanitary  stand- 
point, based  on  general  average  typhoid-fever  death- 
rates: 

CHARACTER   OP  WATER-SUPPLY. 

Depreciation  in  dol- 
lars  per  million 
gallons. 

1.  Ground-waters,  except  in  cases  where  pollution  is 

excessive,  or  where  wells  are  driven  in  rock  or 

soil  abounding  in  fissures $0 . 00 

2.  Filtered  waters   (assuming  modern  methods  of 

construction  and  operation) 0 .00 

3.  Surface-waters: 

(a)  Ordinary  upland  waters,  with  insignifi- 
cant contamination $0.00  to  $15.00 

(6)  Slightly  contaminated  waters,  with  good 

storage  in  lakes  or  large  reservoirs.  ...  10.00  to  50.00 

(c)  River- waters,  slightly  contaminated,  little 

or  no  storage 25.00  to  100.00 

(d)  River- waters,  much  contaminated,  little 

or  no  storage 50.00  to  200.00 

EFFECT  OF    TURBIDITY,  COLOR,   AND  ODOR 

It  has  been  shown  that  the  aesthetic  deficiency  of 
water  depends  upon  three  variable  characteristics, 
which  may  have  many  different  combinations;  conse- 


j  8  The  Value  of  Pure  Water 

TABLE  13. 

EXAMPLES  OF  WATERS  WITH  DIFFERENT  PHYSICAL  CHARACTER- 
ISTICS. 


Per  cent 

Depre- 

Tur- 

of ob- 

ciation 

City. 

Source  of  supply. 

bid- 
ity. 

Color. 

Odor. 

jecting 
con- 

per 
million 

sumers  . 

gallons. 

GROUND-WATERS. 


Camden  N.  J.. 

Driven  wells 

o 

1 

o 

o 

0  00 

Flatbush,  L.  I  .  .  . 

Driven  wells  

o 

o 

o 

o 

0  00 

Lowell,  Mass.  .  .. 

Driven  wells  

0 

10 

0 

5 

1.00 

SURFACE-WATERS. 


Portland,  Me.  ... 
Boston,  Mass.  .  .  . 

Cleveland,  Ohio  . 
Worcester,  Mass  . 
New  York  City.  . 

Lake  Sebago  
Sudbury  and  Nashua 
rivers  
Lake  Erie  
Storage  reservoirs.  .  .. 
Croton  River  

1 

3 

18 
2 

4 

15 

25 
5 
30 
20 

2v 

2v 
1.5v 
3v 
3v 

20 

30 
30 
40 
55 

$4.00 

6.00 
6.00 
8.00 
11  00 

Brooklyn,  N.Y.. 

Jersey  City,  N.  J. 
Watertown.N.Y. 
Springfield,  Mass. 
Bangor,  Me  
Pittsburg,  Pa.  .  . 
Philadelphia,  Pa. 
St.  Louis,  Mo.  .  .  . 

Ponds  and  driven  wells 
on  Long  Island.  .  .    . 
Rockaway  River.  ..    . 
Black  River  
Ludlow  reservoir.  ..    . 
Penobscot  River.  .  .    . 
Allegheny  River.  .  .    . 
Schuylkill  River.  .  .    . 
Mississippi  River.  ..    . 

3 

4 
6 
5 
6 
64 
150 
200 

13 
32 
70 
27 
65 
30 
10 
30 

1.50 
2v.lg 
3v 
4g 
3v.lm 
3v.2m 
3v.2m 
3v.2m 

36 
38 
55 
104 
59 
87 
102 
127 

7.20 
7.60 
11.00 
20.80 
11.80 
17.40 
20.40 
25.40 

Some  of  the  above  figures  do  not  represent  present  conditions.  For  exam- 
ple, Watertown,  N.  Y.,  now  has  filtered  water;  St.  Louis  uses  a  chemically 
treated  water;  etc. 


quently  it  is  difficult  to  classify  the  water-supplies  of  the 
country  on  this  basis.  For  this  reason  the  few  typical 
examples  given  in  Table  13  may  be  more  instructive 
than  any  attempt  at  a  general  classification. 

It  will  be  seen  from  the  above  figures  that,  while  the 


Application  of  the  Formulae  39 

general  attractiveness  of  a  water  is  of  less  importance 
than  its  sanitary  quality,  yet  it  is  by  no  means  insignifi- 
cant. For  instance,  such  a  water  as  that  now  supplied 
to  New  York  City  from  the  Croton  River  has  a  depre- 
ciation of  $11  per  million  gallons,  or  nearly  a  million  and 
a  half  dollars  a  year  for  a  daily  supply  of  350  million 
gallons.  At  4  per  cent  this  represents  the  interest  on 
about  $35,000,000,  a  sum  several  times  as  large  as  the 
cost  of  filtration.  An  algae-laden  water  like  that  of 
Ludlow  Reservoir  at  Springfield,  Mass.,  has  a  deprecia- 
tion of  more  than  $20  per  million  gallons,  because  of 
its  odor  and  turbidity.  A  colored  water  like  that  of  the 
Black  River  at  Watertown  before  filtration  has  a  de- 
preciation of  $11,  while  a  turbid  water  like  that  of  the 
Mississippi  River  at  St.  Louis  gives  $25. 

In  most  surface-waters  the  physical  characteristics 
vary  greatly  at  different  times  of  the  year.  During  the 
spring  and  fall,  for  instance,  the  color  and  turbidities 
may  be  high  on  account  of  rains,  while  during  the  sum- 
mer the  water  may  have  bad  odors  due  to  microscopic 
organisms.  The  following  depreciations  of  certain 
reservoir  waters,  calculated  as  above  described,  serves 
well  to  show  this  seasonal  variation. 


The  Value  of  Pure  Water 


TABLE  14. 

ORDINARY  SEASONAL  VARIATION  IN  THE  DEPRECIATION  OP  A  SUR- 
FACE-WATER DUE  TO  CHANGES  IN  TURBIDITY,  COLOR,  AND  ODOR. 


Month. 

Turbid- 
ity. 

Color. 

Odor. 

Per  cent 
objecting 
con- 
sumers. 

Deprecia- 
tion per 
million 
gallons. 

January  
February.  .  .  . 
March  

6 

8 

7 

25 

28 
27 

3t> 
3v 
3v 

44 
47 
45 

$8.80 
9.40 
9  00 

April  

5 

22 

3v-f 

40 

8  00 

May 

g 

25 

(3v.O  500  3m) 

49 

q  en 

June 

7 

30 

(3t>  0  3m         ) 

48 

0  60 

July 

4 

22 

(3v  0  50  0  5m) 

43 

8  60 

August  
September.  .. 
October  
November  .  .  . 
December.  .  . 

Average.  .  . 

4 
3 

4 
3 
4 

25 
30 
28 
26 
25 

(3v.2.  00.5m) 
(3v.l.  00.5m) 
(3v.l.  00.5m) 
(3t?.0.3m         ) 
(3v.0.3m         ) 

62 
63 
49 
40 
42 

12.40 
12.60 
9.80 
8.00 
8.40 

$9  53 

TABLE  15. 

EXTREME  CASE  OF  SEASONAL  VARIATION  IN  THE  DEPRECIATION  OF  A 
SURFACE-WATER  DUE  CHIEFLY  TO  GROWTHS  OF  ALG.E. 


Month. 

Turbid- 
ity. 

Color. 

Odor. 

Per  cent 
of  object- 
ing con- 
sumers. 

Deprecia- 
tion per 
million 
gallons. 

January 

1 

25 

2v 

26 

«K    9rt 

February  
March  

1 
2 

42 
40 

2v 
2v 

34 
35 

6.80 
7  00 

April  

2 

41 

2v 

36 

7  20 

May  

5 

38 

3v 

48 

9  60 

10 

43 

20 

58 

11  60 

July  

15 

45 

30 

87 

17  40 

August  
September  
October  

25 
25 
15 

64 
57 

28 

40 
40 
3a 

137 
133 

78 

27.40 
26.60 
15  60 

November 

5 

24 

3v 

41 

c   on 

December  . 

3 

26 

2v 

QA 

fi  00 

Average  

«1O  Qft 

Benefits  of  Filtration 


EFFECT  OF   HARDNESS 

The  waters  of  New  England  are  comparatively  soft, 
although  in  some  instances  the  ground-waters  are  hard. 
In  the  Middle  West,  on  the  contrary,  most  of  the  sur- 
face-waters are  quite  hard,  and  in  some  cases  the  hard- 
ness is  excessive.  The  following  figures  serve  to  give 
an  idea  of  the  range  in  the  depreciation  of  waters  due 
to  hardness. 

TABLE  16. 


State. 

City  or  town. 

Source  of  supply. 

Total 
hard- 
ness 
(parts 
per  mil- 
lion). 

Depre- 
ciation 
per  mil- 
lion 
gallons. 

Maine  

Augusta.  .  .  . 

Kennebec  River  .  . 

20 

$2  00 

<  < 

Waterville.  . 

Messalonskee  River. 

15 

1   50 

Massachusetts.  . 

Boston  

Sudbury  and  Nashua 
rivers  

12 

].20 

tt 

ft 

New  York.. 

Cambridge.  . 
Pittsfield!  .  .  . 
New  York.  .  . 

Storage  reservoir.  .  .  . 
Storage  reservoir.  ..  . 
Croton  River  

33 
50 
40 

3.30 
5.00 
4.00 

<  t 

Albany 

Hudson  River 

64 

6  40 

1  1 

Oswego  

Oswego  River  

191 

19.10 

Pennsylvania.  . 
Ohio 

Philadelphia. 
Toledo 

Schuylkill  River.  .  .  . 
Maumee  River 

179 
200 

17.90 
20  00 

4  I 

Columbus 

Scioto  River 

335 

33  50 

It 

England.  .  .  . 

Warren  
London  . 

Mahoning  River  .... 
Chelsea  Company 

578 
215 

33.50 
21  52 

London.  .  . 

East   London  Com- 

pany. . 

243" 

24  30 

Benefits  of  Filtration 

The  filtration  of  a  water  improves  its  quality  in  many 
ways.     It  not  only  makes  the  water  wholesome,  but  it 


42  The  Value  of  Pure  Water 

improves  its  general  attractiveness.  By  using  a  prop- 
erly designed  filter-plant,  supplemented  if  necessary 
by  sedimentation  or  aeration  or  chemical  treatment 
according  to  local  needs,  an  infected  water  may  be  made 
safe  to  drink,  a  turbid  water  may  be  clarified,  a  colored 
water  rendered  colorless,  a  bad-smelling  water  made 
savory,  and  a  hard  water  made  soft.  By  the  applica- 
tion of  the  formulae  above  described  the  beneficial 
effects  of  filtration  may  be  clearly  demonstrated. 

Sanitary  qualify. — The  following  figures  show  to 
what  extent  the  sanitary  value  of  a  polluted  public 
water-supply  is  increased  by  an  efficient  system  of 
filtration: 

Lawrence,  Mass.: 

Water-supply,  Merrimack  River,  filtered  by  a  slow  sand-filter. 

Population,  70,000. 

Water  consumption,  40  gallons  per  capita  daily. 

Before  filtration  the  typhoid-fever  death-rate  was  121  per 
100,000;  since  then  it  has  been  26. 

Before  filtration  D=2.75(121-20)X-W=$693. 

After  filtration  D=2.75(26-20)X¥/=$41. 

Increase  in  sanitary  value =$693— $41  =$652  per  million  gal- 
lons, or  $665,000  per  year,  or  $9.50  per  year  per  capita. 

Albany,  N.  Y.: 

Water-supply,  Hudson  River,  filtered  by  sand-filter. 

Population,  95,000. 

Water  consumption,  165  gallons  per  capita  daily. 

Before   filtration    the   typhoid-fever    death-rate  was   104   per 

100,000;   since  then  it  has  been  26. 
Before  filtration  Z>  =  2.75(104- 20)  X  i§§=$140. 


Benefits  of  Filtration  43 

Albany,  N.  Y.   (Continued): 

After  filtration  £>  =  2.75(26-20)Xl$g=$10. 
Increase  in  sanitary  value=$140  — $10=$130  per  million  gal- 
lons, or  $450,000  per  year,  or  $4.75  per  capita  per  year. 

Binghamton,  N.  Y.: 

Water-supply,  Susquehanna  River,   filtered  by  a  mechanical 

filter. 

Population,  42,000  (approximately). 
Water  consumption,  160  gallons  per  capita  daily. 
Typhoid-fever  death-rate  before  filtration,  49;  after  filtration, 

11  per  100,000. 

Before  filtration  D  =  2.75(49- 11)  XH* =$65. 
After  filtration  D  =  2.75(11-11)X-HHHO. 
Increase  in  sanitary  value =$65.00  per  million  gallons,  or  $160,- 

000  per  year,  or  $3.80  per  capita  per  year. 
Watertown,  N.  Y.: 

Water-supply,  Black  River,  filtered  by  mechanical  filter. 
Population,  25,500  (approximately). 
Water  consumption,  160  gallons  per  capita  daily. 
Typhoid-fever  death-rate  before  filtration,  97  per  100,000;  after 

filtration,  27. 

Before  filtration  D  =  2.75(97-20)X^=$132.34. 
After  filtration  D =2.75(27 -20) Xi^  =  12.0. 
Increase  in  sanitary  value  =$120. 34  per  million  gallons,  or  $175,- 

000  per  year,  or  $6.90  per  capita  per  year. 

Illustrations  like  the  above  might  be  multiplied,  but 
the  four  cases  selected  are  sufficient  to  illustrate  the 
general  fact.  It  is  easily  seen  from  them  that  the  filtra- 
tion of  a  polluted  public  water-supply  increases  to  a 
very  great  extent  the  vital  assets  of  a  community,  and 
the  increase  in  most  cases  is  many  times  greater  than 
the  cost  of  constructing  and  operating  the  works. 


44  The  Value  of  Pure  Water 

Money  paid  to  the  doctor,  the  apothecary,  and  the 
undertaker  is  not,  in  one  sense,  a  loss  to  a  community, 
as  it  is  merely  a  transference  of  money  from  one  man's 
pocket  to  another's,  but  in  the  broader  sense  any  loss 
of  productive  capacity  or  any  unnecessary  expenditure 
is  a  loss.  Deaths  from  typhoid  fever  and  from  other 
diseases,  however,  represent  a  very  material  loss  of 
the  productive  capacity  of  a  community,  and  conse- 
quently a  decrease  in  what  may  be  termed  the  "vital 
assets."  In  the  case  of  the  city  of  Albany,  for  instance, 
the  increased  worth  of  the  water  to  the, city,  because  of 
its  efficient  filtration,  amounts  to  $475,000  per  year, 
of  which  at  least  $350,000  may  be  considered  as  a  real 
increase  in  the  vital  assets  of  the  city. 

If  in  the  formula  D  =  $2.7S(T-N)  we  let  T-N=it 
then  ^  =  $2.75;  that  is,  a  decrease  in  the  typhoid-fever 
death-rate  of  i  per  100,000  causes  an  increase  in  the 
vital  assets  of  the  city  of  $2.75  for  each  million  gallons 
of  the  public  water-supply  (assuming  this  to  be  TOO 
gallons  per  capita),  or  $0.10  per  capita  per  year  for 
each  unit  reduction  of  the  typhoid-fever  death-rate  per 
100,000.  In  other  words,  the  decrease  in  the  typhoid 
death-rate  per  100,000  divided  by  10  gives  the  increased 
vital  assets  of  the  community  in  dollars  per  capita  per 
year.  Thus,  in  the  case  of  Albany,  above  given,  the 
reduction  in  the  typhoid- fever  death-rate  was  78  per 


/  0'-  THi 

f  UNIVERSITY 


Benefits  of  Filtration  45 

100,000.  On  the  basis  of  10  cents  per  capita  per  unit 
decrease,  this  would  amount  to  $0.10X78x95,000  = 
$741,000  per  year,  assuming  a  per-capita  consumption 
of  100  gallons  daily,  or  $450,000  for  a  per-capita  con- 
sumption of  165  gallons  daily,  which  is  the  figure  stated 
above. 

Looking  at  the  matter  in  another  way,  it  may  be  said 
that  the  purification  of  a  polluted  water  is  a  sort  of  life- 
insurance  for  the  people,  the  value  of  which  is  equal  to 
10  cents  per  capita  for  each  unit  decrease  in  the  typhoid- 
fever  death-rate  per  100,000  which  it  brings  about. 
Such  a  sum  capitalized  represents  a  large  amount  of 
money.  In  Albany,  for  example,  where  the  typhoid- 
fever  death-rate  has  been  reduced  78  per  100,000,  the 
annual  saving  of  life-value  would  be  $7.80  per  capita. 
Capitalized  on  the  basis  of  an  annual  life-insurance 
premium  of  $17  per  thousand,  this  would  represent  an 
insurance  policy  of  about  $460  per  year  for  each  inhab- 
itant, or  $2,300  for  each  head  of  a  family. 

Physical  quality. — The  figures  of  Table  17  show  the 
effect  of  filtration  on  the  attractiveness  of  waters — 
that  is,  upon  the  aggregate  effect  of  their  physical  char- 
acteristics. 

These  figures  do  not  pretend  adequately  to  rep- 
resent the  conditions  in  any  of  the  cities  included  in  the 
list,  as  the  analysis  in  each  case  represents  only  one 


46 


The  Value  of  Pure  Water 


Hi 

||  S 


0000000 


0 

'^ 


. 

C  to 


O5 
CO  < 


S     S 


ja  (N    ^(M    ^  T-H    -^rHCOT-lCOi-lCCrHC^O 

CO        CO        i-H         CO 


t-i        M        t-  t3 

1  1  1  1  1  II 


IS  I   1  182 


1 


Benefits  of  Filtration  47 

date.  They  are,  however,  typical  of  what  the  filters 
in  the  various  places  are  doing,  and  they  indicate  that 
the  increased  value  of  the  water,  because  of  its  nitration, 
is  as  great  as  the  cost  of  the  works — in  some  cases  it  is 
even  greater.  Thus  if  the  effect  of  filtration  on  the 
sanitary  qualities  of  these  waters  is  entirely  ignored, 
and  only  its  effect  on  their  physical  qualities  considered, 
the  filtration  of  these  supplies  would  still  be  a  profitable 
undertaking  from  a  financial  standpoint.  If  the  sani- 
tary qualities  were  also  considered,  the  advantages  of 
filtration  would  be  found  to  be  many  times  greater. 

Water-softening. — The  following  figures  will  illustrate 
the  financial  value  of  water-softening  plants: 

Winnipeg,  Manitoba: 

Hardness  of  water  before  treatment 580 

Hardness  of  water  after  chemical  treatment  and  filtra- 
tion          193 

Reduction  in  hardness 387 

Increased  value  of  water  due  to  water-softening  process, 

per  million  gallons $38 . 70 

Oberlin,  Ohio: 

Hardness  of  raw  water 170 

Hardness  of  raw  water  after  chemical  treatment  and  fil- 
tration   48 

Reduction  in  hardness 122 

Increased  value  of  water  due  to  water-softening  per  mil- 
lion gallons $12  20 

These  figures  refer  only  to  water  used  for  domestic 


48  The  Value  of  Pure  Water 

purposes.  If  industrial  uses  also  were  considered,  the 
advantages  of  water  softening  would  be  still  more 
evident. 

At  the  present  time  there  are  not  many  water-soften- 
ing plants  in  existence  in  connection  with  municipal 
supplies,  but  the  advantages  to  be  gained  are  very 
great,  and  are  becoming  appreciated  by  the  managers  of 
railroads  and  industrial  establishments.  With  a  better 
understanding  of  the  practical  benefits  to  be  derived 
from  the  use  of  soft  water,  it  may  be  confidently  ex- 
pected that  during  the  next  ten  years  the  number  of 
municipal  water-softening  plants  will  very  greatly 
increase. 

Cost  of  Filtration 

In  order  that  the  reader  may  have  some  basis  with 
which  to  compare  the  cost  of  nitration  with  the  bene- 
fits derived  the  following  paragraph  is  quoted  from  a 
paper  by  Allen  Hazen  on  "Purification  of  Water  for 
Domestic  .Use,"  read  at  the  International  Engineering 
Congress  in  St.  Louis  in  1904.  (Transactions  Am.  Soc. 
C.  E.,  Vol.  LIV,  Part  D,  1905.) 

'  *  During  the  decade  there  has  been  a  wonderful 
advance  in  the  design  and  management  of  purification 
plants.  The  effect  of  these  changes  has  had  two  effects 


Cost  of  Filtration  49 

upon  the  cost.  On  the  one  hand,  more  exacting  require- 
ments have  constantly  led  to  the  use  of  better  and 
more  adequate  appliances  and  to  more  thorough  sys- 
tems of  operation,  and  this  has  tended  to  increase  the 
cost.  On  the  other  hand,  improvements  in  design  and 
the  development  of  mechanical  appliances  to  perform 
parts  of  the  work  formerly  accomplished  by  hand  labor 
have  tended  to  reduce  the  cost.  On  the  whole,  it  is, 
perhaps,  fair  to  state  that  the  improved  methods  and 
the  increased  efficiency  have  been  secured  without  any 
material  change  in  the  cost  of  the  process,  although,  of 
course,  there  are  many  exceptions,  some  in  one  direc- 
tion and  some  in  the  other. 

"As  a  general  average,  with  a  well-designed  modern 
plant  adapted  to  its  work,  the  cost  of  filtering  water, 
exclusive  of  pumping,  but  including  all  costs  of  operating 
the  filters  and  furnishing  the  supplies  required,  and 
including  the  interest  on  the  cost  of  the  works  and  a 
reasonable  allowance  for  repairs  and  depreciation,  will 
amount  to  about  $10  per  million  gallons,  or  one  cent 
per  thousand  gallons  of  filtered  water.  Occasionally, 
with  very  easily  treated  water,  and  with  conditions 
favorable  for  cheap  construction,  the  cost  may  be  as 
low  as  $6  or  $8  per  million  gallons.  On  the  other  hand, 
with  waters  which  are  difficult  to  treat,  or  where  the 
conditions  of  construction  are  difficult,  the  cost  may  be 


50  The  Value  of  Pure  Water 

increased  to  $15  or  even  $20  per  million  gallons.  In  a 
general  way,  the  purification  of  the  water  adds  from 
10  to  20%  to  the  entire  cost  of  furnishing  and  supply- 
ing water  to  an  American  city.  The  percentage  is  usu- 
ally less  as  the  works  for  securing  the  water  are  more 
extensive.  Where  water  is  carried  long  distances  (the 
absolute  cost  of  purification  remaining  the  same)  the 
percentage  is  much  less  than  where  water  is  obtained 
from  sources  in  the  immediate  vicinity.  This  cost  of 
filtration,  although  a  small  percentage  of  the  whole  cost 
of  water-works,  has  been  large  enough  to  prove  a  sub- 
stantial obstacle  to  the  adoption  of  filters  in  many 
cases." 


Summary 

In  the  foregoing  study  attention  has  been  called  to 
the  following  propositions: 

1.  Pure  water  as  compared  with  impure  water  has  a 
real  financial  value  to  a  community. 

2.  This  value  may  be  measured  by  determining  what 
impure  water  costs  the  community. 

3.  There   are   three   principal   characteristics   which 
affect  the  value  of  water  to  the  general  consumer — its 
sanitary  quality,  its  general  attractiveness,  and  its  hard- 
ness. 

4.  A  formula  is  suggested  for  computing  the  effect  of 


Summary  5 1 

the  sanitary  quality  of  water  on  its  financial  value  to  a 
community.  It  is  based  on  the  typhoid-fever  death- 
rate. 

5.  A  formula  is  suggested  for  computing  the  effect  of 
the  general  attractiveness  of  water  on  its  value  to  con- 
sumers.    It  is  based  on  the  physical  characteristics  of 
turbidity,  color,  and  odor. 

6.  A  formula  is  suggested  for  computing  the  effect  of 
the  hardness  of  water  on  its  value  to  the  consumers.     It 
it  based  on  the  use  of  soap  in  the  household. 

7.  Considered  from  the  financial  aspect  alone,  and 
disregarding  all  humanitarian  considerations,  the  nitra- 
tion of  a  polluted  water-supply  adds  very  greatly  to  the 
vital  assets  of  a  community;  hence,  as  a  mere  business 
proposition,  no  city  can  afford  to  allow  an  impure  water- 
supply  to  be  publicly  distributed. 

8.  The  advantages  to  a  community  of  having  a  water- 
supply,  not  only  safe  but  also  attractive  in  appearance, 
taste,  and  odor,  are  material  from  a  financial  aspect. 
The  increased  value  of  many  waters  because  of  the  im- 
provement in  their  aesthetic  qualities  alone  justifies  the 
cost  of  filtration. 

9.  Water-softening  at  present  does  not  receive  the 
attention  it  deserves  at  the  hands  of  municipal  au- 
thorities.    The  economic  advantages  to  be  gained  by 
removing  the  hardness  of  water  are  so  great  that,  in 


52  The  Value  of  Pure  Water 

many  cases,  the  saving  to  the  ordinary  water-consumer 
justifies  the  cost  of  softening  water. 

10.  The  formulae  here  suggested  and  the  detailed  re- 
sults derived  from  their  use  are  not  to  be  considered  as 
of  great  accuracy,  as  the  assumed  data  are  not  fully 
adequate.  They  are  given  merely  to  show  the  possi- 
bility of  computing  the  value  of  pure  water  in  terms  of 
dollars  and  cents,  and  to  illustrate  the  financial  value 
of  filtration  and  justify  its  cost. 


WHAT  IS  "PURE  AND  WHOLESOME  WATER'*? 

(Extract  from  an  address  delivered  at  Albany,  October  5, 
1905,  at  a  Conference  of  the  Sanitary  Officers  of  New  York 
State  on  "The  Pollution  of  Streams  and  the  Natural  Agencies 
of  Purification.") 

is  always  difficult  to  adhere  to  strict 
definitions  when  popular  words  are  used 
in  a  scientific  sense.  The  very  simplicity 
of  the  expression  "pure  water"  makes  it  hard  to 
define — especially  so  to  a  chemist  who  knows  that  no 
natural  waters  are  absolutely  pure  and  that  at  best 
he  can  apply  the  term  only  in  a  relative  sense. 

In  the  first  place,  it  must  be  recognized  that  river- 
waters  in  a  state  of  nature  vary  greatly  in  purity;  some 
are  clear,  colorless,  and  sparkling,  some  are  muddy  and 
high-colored,  some  are  saline,  some  are  chalybeate, 
some  are  sulphurous.  Of  these  various  waters  part  are 
wholesome,  part  are  not;  and  their  wholesomeness  does 
not  depend  upon  the  characteristics  just  mentioned. 
In  the  second  place,  river-waters  may  receive  additions 

of  artificial  substances  of  several  classes — those  which 

53 


54  The  Value  of  Pure  Water 

do  not  injure  its  quality  in  any  material  or  notice- 
able way,  such  as  common  salt  or  lime;  those  which 
injure  its  appearance  or  odor  or  impregnate  it  with 
objectionable  chemical  constituents,  but  which  do  not 
tend  to  make  the  water  disease-producing,  such  as 
dyestuffs;  those  which  tend  to  render  the  water 
poisonous,  as  the  salts  of  lead  or  tin;  and  those  which 
tend  to  make  the  water  capable  of  producing  infectious 
diseases,  such  as  sewage.  Of  course  substances  of  any 
of  these  classes  added  to  the  water  in  excessive  amounts 
injure  its  quality  for  some  uses.  In  the  third  place,  we 
must  recognize  in  practice  as  well  as  in  theory  that 
when  water  produces  diseases  it  does  so  chiefly  by 
transmitting  living  organisms  or  their  spores  from  one 
human  being,  or  possibly  from  some  animal,  to  another 
human  being  or  animal.  In  the  fourth  place,  it  must 
be  remembered  that  in  public  water-supplies  the  quality 
of  the  water  must  be  considered  for  industrial  uses  as 
well  as  for  drinking.  And  lastly,  the  fact  must  not 
be  overlooked  that  not  all  river-waters  are  used  for 
public  water-supplies  and  that  it  is  not  necessary  to 
maintain  in  such  the  same  degree  of  purity  as  when 
they  are  to  be  used  for  drinking.  In  this  case  the 
standard  is  not  a  hygienic  one,  but  an  aesthetic  one. 

Our   ordinary   vocabulary   applies   to   objectionable 
waters  such  words  as  contaminated,  polluted,  infected, 


Epithets  Applicable  to  Water          55 

befouled,  defiled,  tainted,  corrupted,  stained,  impure,  soiled, 
putrid,  etc.,  while  to  describe  good  and  generally  satis- 
factory waters  we  have  only  the  positive  words  pure, 
safe,  and  wholesome.  With  so  many  words  in  use, 
either  our  language  is  redundant  or  we  are  using  words 
carelessly  and  without  regard  to  their  exact  meaning. 
In  the  following  arrangement  of  definitions  I  run  the 
risk  of  contradicting  some  authorities,  but  I  believe  it 
to  be  representative  of  the  best  current  usage  and, 
at  any  rate,  to  make  for  clearness  of  expression. 


Epithets  Especially  Applicable  to  Waters  in  a 
Natural  State 

A  stained  water  is  one  which  is  colored  by  vegetable 
extractives  from  leaves,  soil,  etc.  (The  term  "colored 
water"  is  a  better  one.) 

A  soiled  water  is  one  made  dirty  by  washings  from 
the  soil,  that  is,  by  clay,  silt,  etc.  (The  term  * 'turbid" 
is  a  better  one.) 

A  tainted  water  is  one  which  has  an  unpleasant  odor, 
due  to  the  decomposition  of  organic  matter,  to  the 
presence  of  algse,  etc. 

A  putrid  water  is  one  in  which  the  decomposition  of 
organic  matter  has  reached  such  a  degree  that  all 
the  dissolved  oxygen  has  disappeared  and  the  water 


56  The  Value  of  Pure  Water 

become  offensive  to  sight  or  smell.     (This  term  is  more 
often  applied  to  polluted  waters.) 

An  impregnated  water  is  one  which  contains  chemic- 
ally dissolved  such  substances  as  lime,  magnesia,  soda, 
salt,  iron,  hydrogen  sulphide,  etc.,  in  quantities  suffi- 
cient to  be  objectionable  for  the  purpose  for  which 
the  water  is  to  be  used.  (In  small  quantities  the  pres- 
ence of  these  substances  might  pass  without  comment.  ) 

Epithets  Applicable  to  Water  with  Artificial 
Substances  Admixed 

A  polluted^z&ater-is  one  which  has  received  and  still 
holds  the  excreta  of  human  beings  or  animals,  or  the 
waste  product  of  human  industry.  The  word  '  'pollution  '  ' 
may  be  used  as  a  general  term  to  cover  all  substances 
artificially  admixed  with  water.  Polluting  matter  may 
be  divided  into  that  which  contaminates  and  that 
which  merely  tends  to  make  the  water  foul. 

A-befouled  water_Qr_a.  defiled  water  is  one  which  has 
received  and  holds  matter  tending  to  make  it  foul, 
unsightly,  or  ill-smelling,  but  which  is  not  of  excre- 
mentitious  origin. 

water  is  one  which  has  received  and 


holds    excrementitious  matter,  whether    from    human 
beings  or  animals.     Such  a  water  does  not  necessarily 


Epithets  Applicable  to  Water          57 

contain  disease  germs,  though  this  must  be  always 
considered  as  possible.  (The  word  '  'contamination"  is 
often  used  as  a  synonym  for  pollution  and  given  a 
more  general  application,  but  its  restricted  meaning 
seems  to  serve  a  more  useful  purpose.) 

An  infected  water  is  one  which  actually  contains 
pathogenic  bacteria  capable  of  producing  disease. 
Such  disease  germs  are  nearly  always  of  excrementitious 
origin. 

A  poisoned  water  is  one  which  contains  some  poisonous 
chemical  substance.  (This  occurs  rarely,  except  in 
the  case  of  lead.) 

It  will  be  seen  that  river-waters  may  be  stained,  or 
soiled,  or  tainted,  and  even  putrid,  and  yet  not  be 
polluted,  while  polluted  waters  need  not  necessarily 
be  visibly*  stained  or  soiled  or ,  tainted. 

A  water  may  be  polluted  and  yet  not  be  contam- 
inated with  sewage  or  contain  disease  germs;  a  water 
may  be  contaminated  even  and  yet  not  actually  con- 
tain disease  germs  (this  statement  is  only  tentatively 
advanced);  but  a  contaminated  water  is  necessarily  a 
polluted  water,  while  an  infected  water  is  both  polluted 
and  contaminated.  A  sharp  distinction  must  be  made 
between  befouled  waters  and  contaminated  waters,  as 
these  terms  distinctly  separate  sewage  from  trade  wastes. 

Now,  what  are  pure  and  safe  and  wholesome  waters? 


58  The  Value  of  Pure  Water 

The  last   two   have  nearly   equivalent   meanings . 
safe  water  may  be  taken  as  one  which  is  neither  poison- 
ous nor  infected  nor  contaminated,  that  is,  one  which 
is  not  liable  to  cause  actual  disease. 

A  ?<»Jt.ni/>.s(ftftff  water  js_a  safe  water  and  one  which  is 
not  befouled,  stained,  soiled,  or  tainted  enough  to 
injure  the  health  or  to  make  the  water  too  unattractive 
to  use.  Preferably  also  it  should  be  well  aerated. 

A  i>ure^water  implies  much  more;  it  must  not  only 
be  not  poisonous,  not  infected,  not  contaminated,  and 
not  appreciably  befouled,  but  besides  this  it  must  be 
practically  unstained,  unsoiled,  and  untainted,  as  well 
as  unimpregnated  with  noticeable  amounts  of  objection- 
able chemical  salts.  Obviously  there  may  be  different 
degrees  of  purity,  but  absence  of  contamination  and 
practical  absence  of  befoulment  must  be  considered 
in  any  case  as  a  sine  qua  non. 

Now  that  we  have  denned  these  terms  from  a  sani- 
tarian's point  of  view  let  us  see  how  the  analyst  defines 
them  and  what  tests  can  be  applied  to  differentiate 
them.  We  cannot  go  into  this  subject  minutely  with- 
out consuming  too  much  time,  but  it  should  be  noted 
that  the  tests  which  make  up  the  water  analysis  may 
be  divided  into  four  groups — physical,  chemical,  micro- 
scopical, and  bacteriological — which  serve  different 
purposes. 


Epithets  Applicable  to  Water          59 

Waters  naturally  stained,  soiled,  or  tainted  may  be 
studied  by  physical  tests  alone,  which  can  be  made 
out  of  doors  with  very  simple  apparatus,  though  in 
studying  tainted  waters  a  microscopical  examination 
of  the  algae,  etc.,  is  of  great  value. 

Befouled  waters  must  be  studied  chemically  as  well 
as  physically  and  microscopically.  The  amount  of 
organic  matter,  nitrogenous  and  carbonaceous,  must 
be  determined  as  well  as  some  of  the  mineral  constitu- 
ents. Sometimes,  and  especially  when  the  befoulment 
is  large,  the  dissolved  gases,  oxygen  and  carbonic  acidr 
must  be  determined  to  see  if  there  is  danger  of  putridity. 
Bacteriological  examinations  are  also  sometimes  helpful.. 

Bacteriological  examinations  are  especially  necessary,, 
however,  in  the  study  of  contamination.  Here  they  are 
absolutely  essential,  and  the  tests  must  be  such  as  to 
reveal  not  only  the  number  of  ordinary  water-bacteria 
but  those  which  are  commonly  associated  with  fecal 
matter  and  sewage.  Among  these  the  test  for  the 
colon  bacillus  is  of  most  value,  as  the  presence  of  this- 
organism  and  its  relative  abundance  is  the  best  index  of 
contamination  that  we  have.  It  is  desirable,  however,, 
and  often  necessary  to  have  chemical,  physical,  and  mi- 
croscopical examinations  accompany  the  bacteriological 
tests.  Indeed,  these  four  tests  are  now  generally  recog- 
nized as  constituting  a  modern  sanitary  water-analysis, 


60  The  Value  of  Pure  Water 

and  their  testimony  should  be  interlocking,  one  part 
helping  to  explain  the  other. 

Beyond  proving  a  water  to  be  contaminated  we  can- 
not go  at  present  with  our  laboratory  methods.  We 
cannot  tell  by  analysis  with  certainty  that  a  water 
is  or  is  not  actually  infected  with  disease  germs.  I 
do  not  mean  that  it  is  absolutely  impossible  to  say 
that  a  water  contains,  for  instance,  the  germs  of  typhoid 
fever — for  typhoid-fever  germs  may  be  and  have  been 
isolated  from  water  samples — but  our  tests  are  not  so 
reliable  that  if  we  obtained  a  negative  result  we  could 
say  that  the  water  was  not  infected.  We  hope  the 
time  will  come  when  we  may  do  this,  but  we  cannot 
do  it  now. 

At  present,  therefore,  in  order  to  be  on  the  safe  side, 
we  must  consider  contamination  as  potential  infection, 
inasmuch  as  infection  originates  in  contamination,  and 
we  must  deal  with  a  contaminated  water  as  though  it 
were  infected. 

The  interpretation  of  a  water-analysis  is  a  difficult 
matter  and  one  which  requires  a  wide  experience  with 
different  classes  of  natural  and  polluted  waters.  To 
distinguish  between  contamination  and  befoulment  is 
often  a  difficult  matter  even  for  the  expert.  In  all 
cases  a  knowledge  of  the  natural  or  normal  quality 
of  the  water  must  be  known,  or  at  least  mentally  esti- 


Epithets  Applicable  to  Water         61 

mated,  before  the  results  of  the  analysis  can  be  properly 
interpreted.  It  is  for  this  reason  that  a  knowledge  of 
the  source  of  the  water  is  necessary  to  the  analyst  and 
that  modern  sanitary  science  lays  so  much  stress  upon 
the  importance  of  sanitary  inspection. 

For  an  ordinary  man  to  draw  a  conclusion  from  the 
figures  of  a  chemical  analysis  is  like  trying  to  determine 
the  state  of  business  by  studying  the  stock  quotations 
as  they  appear  for  a  few  moments  on  the  ticker.  If 
he  has  a  mental  picture  of  all  that  has  happened  on 
the  market  for  many  weeks,  the  quotations  may  mean 
something  to  him,  but  otherwise  they  do  not. 


THE  DISADVANTAGES  OF  HARD  WATER 

(From  a  lecture    delivered   at   the    Brooklyn    Polytechnic 
Institute,  January  9,  1906.) 

waters  have  always  been  considered 
objectionable  for  common  use.  Universal 
experience  is  summed  up  in  the  apologetic 
qualification  heard  so  often,  "We  have  good  water 
here,  but  it  is  hard."  In  recent  years  the  economic 
importance  of  hard  waters  has  been  lost  sight  of  to  a 
considerable  extent,  in  view  of  the  greater  prominence 
of  sanitary  matters.  Engineers  and  manufacturers  are 
now  studying  the  subject  anew,  and  the  more  it  is 
studied  the  more  its  importance  becomes  apparent. 
It  is  seen  that  in  some  industries  the  difference  between 
a  hard  water  and  a  soft  water  may  mean  the  difference 
between  loss  and  profit  on  the  balance  sheet;  in  others 
it  may  mean  a  change  of  the  location  of  a  factory. 
It  may  mean  a  difference  in  the  quality  of  the  manu- 
factured product,  or  the  success  or  failure  of  some 
chemical  process.  It  may  mean  changes  in  labor,  in 

rates  of  transportation,  in  railroad  time-table  sched- 

62 


Use  of  Hard  Water  in    the  Household  63 

ules:    it  may  mean  accidents,  attended  with   loss    of 
property  and  even  of  human  lives. 

The  term  "hard  water"  should  be  strictly  applied  to 
waters  which  contain  salts  of  calcium  and  magnesium, 
particularly  their  carbonates  and  sulphates,  but  in 
popular  and  local  parlance  it  is  frequently,  though 
erroneously,  applied  to  waters  which  contain  other  sub- 
stances, such  as  iron,  sodium  chloride,  and  even  free 
acids  or  alkalies.  In  studying  the  subject  in  its  gen- 
eral aspect  it  seems  best  to  include  these  other  mineral 
constituents  which  have  a  bearing  on  the  problem. 


Use  of  Hard  Water  in  the  Household 

Hard  water  is  unsatisfactory  for  household  use  for 
several  reasons.  The  money  loss  due  to  the  waste  of 
soap  has  been  already  considered,  but  the  inconve- 
niences of  its  use  are  perhaps  more  important  than  the 
money  loss  involved.  In  using  hard  waters  for  washing 
the  hands  and  for  bathing,  the  calcium  and  magnesium 
stearates  are  precipitated  by  the  soap  and  give  rise  to 
unsightly  scums  in  the  wash-bowl  and  bath-tub.  They 
tend  to  fill  the  pores  of  the  skin,  preventing  a  thorough 
cleansing  and  causing  the  hands  to  chap.  They  also 
prevent  the  formation  of  a  good  lather  in  shaving. 

It  is  in  the  laundry  that  the  effects  of   hard  water 


64  The  Value  of  Pure  Water 

are  most  noticeable.  Not  only  are  large  amounts  of 
soap  required  to  produce  a  lather,  but  the  stearates 
above  mentioned  settle  on  the  clothes,  fill  the  pores,  and 
tend  to  rot  them  and  make  them  look  dingy.  Hard 
waters  also  encourage  the  use  of  strong  soaps,  washing 
compounds,  etc.,  which  may  contain  ingredients  de- 
structive of  the  fabrics. 

In  culinary  operations,  such  as  in  making  tea,  hard 
waters  are  less  satisfactory  than  soft  waters,  as  they 
increase  the  color  but  decrease  the  aroma.  This  is  a 
fact  which  few  housekeepers  do  not  fully  realize,  but 
which  may  be  easily  demonstrated  by  experiment. 
Every  one  knows  that  hard  waters  cause  a  crust  to 
form  on  the  walls  of  the  tea-kettle.  The  same  incrusta- 
tion forms  on  the  interior  of  the  "water  back"  of  the 
kitchen  stove  and  interferes  with  the  proper  operation 
of  water  heating. 

The  physiological  effects  of  ordinary  hard  water,  so 
far  as  known,  are  insignificant,  and  most  of  the  theories 
which  have  been  advanced  to  show  the  great  danger 
of  drinking  distilled  water,  or,  on  the  other  hand,  the 
evil  effects  produced  by  drinking-water  containing 
salts  of  lime,  are  without  substantial  foundation. 
Waters  of  excessive  hardness,  or  those  which  contain 
considerable  amounts  of  sodium  sulphate,  alkalies, 
magnesium  salts,  etc.,  may,  however,  produce  decided 


Use  of  Hard  Water  in  the  Household  65 

physiological  disturbances.  It  is  said  that  persons  of 
a  rheumatic  tendency  often  find  partial  relief  by  chang- 
ing from  a  hard  to  a  soft  water. 

The  taste  of  hard  water  is  largely  a  matter  of  personal 
idiosyncrasy  or  habit.  Some  persons  prefer  hard  water, 
while  others  like  soft  water.  As  a  rule,  water  does  not 
taste  hard  unless  the  hardness  exceeds  50  parts  per 
million.  Much  depends  upon  the  nature  of  the  min- 
eral salts  present  and  a  good  deal  upon  the  sensitive- 
ness of  the  individual. 

Some  tastes  are  particularly  sensitive  to  chlorides, 
others  to  alkalies,  others  to  such  astringents  as  alum 
or  ferrous  sulphate.  The  following  results  of  some 
experiments  on  taste  sensitiveness,  made  by  Mr.  Mel- 
ville C.  Whipple,  are  interesting  in  this  connection. 
Solutions  of  different  strengths  of  some  of  the  more 
common  salts  found  in  drinking-water  were  submitted 
to  about  twenty  individuals  for  the  purpose  of  ascer- 
taining the  smallest  amounts  which  could  be  detected 
by  the  taste.  The  figures  in  the  table  indicate  the 
number  of  observers  who  could  detect  a  taste  in  dis- 
tilled water  containing  the  various  salts  to  the  amounts 
indicated,  though  they  do  not  necessarily  mean  that 
the  particular  taste  could  be  recognized  in  that  dilu- 
tion. It  is  interesting  to  notice  that  in  the  case  of 
well-known  tastes,  such  as  those  of  sodium  chloride 


66 


The  Value  of  Pure  Water 


OQ        S 


1 

*  In  terms  of  parts  per  million  of  chlorine. 

g             N 

00 

1              N          N 

s             * 

t- 

g 

1                 :           -     -« 

O       CO                           N                           CM            NCOCO                                     tO 

0       -                           CO-                      -            -^                                         . 

>0 

0       (N                           -     ;                                                                                            ; 

|          1                 ^       "^                      "            " 

CN                                        (M 

1       "" 

CO                      — 

<N                                           ; 

o     I-H            co 

"*               N        rH               — 

CO 

1     :        ^ 

CO               rH        rl        —M 

N 

1     : 

iH               t-        CM        OlrH 

CO 

§     :        N 

r-HM                         '."* 

""• 

I     : 

WiO 

M                 CO 

8     : 

CO                      •* 

00 

s   '    N 

CM                      CO 

>Q                         ^ 

S     :"     : 

7-1 

»0        —              rl 

rH 

iO          ><N       ^ 

IN     : 

»•« 

(N 

CO       CO          • 

2     :  :   * 

(N 

CM               .     . 

iCi          • 

o       I"*1       ! 

CO 

CO               •    • 

<N                 (N          . 

10          -     .          - 

2 

-     :M     : 

^ 

10          :     : 

o      •  •      • 

:  : 

:   M     :     :     : 

Salts  

Potassium  chloride.  .  .  . 
Potassium  hydroxide.  . 

Sodium  carbonate.  .  .  . 

SnrHnm  chloriHp 

Sodium  hydroxide.  .  .  . 

RnHiiim  nitrnto 

tjjisitijj 

310       0  °                3333       °°       g       S       » 

li  11.11  1111  §  |  |  ! 

;;3      ^  "^^        MMMSb      fc       3       ft       M 

loo    dooo    SSSS    tS    ^    6    OQ 

Use  of  Hard  Water  in  the  Household   67 

and  sodium  carbonate,  there  was  considerable  una- 
nimity among  the  observers,  while  in  the  case  of  tastes 
not  so  well  known  the  differences  in  the  various  limits 
of  taste  were  wide. 

Chlorinated  waters  are  often  the  source  of  much 
annoyance  and  expense  to  the  householder  on  account 
of  their  tendency  to  cause  corrosion  of  the  plumbing. 
The  copper-lined  flush  tanks  with  soldered  seams,  so 
commonly  used,  soon  become  corroded  and  have  to  be 
replaced  in  cities  where  the  amount  of  chlorine  in  the 
water  is  large.  This  is  due  to  galvanic  action  set  up 
between  the  copper  and  the  solder.  This  corrosion  is 
more  likely  to  occur  in  clear  waters  than  in  those  which 
are  so  turbid  that  they  form  deposits  in  the  tanks 
and  so  protect  the  metals  from  the  galvanic  action. 
Instances  are  on  record  where  the  filtration  of  water 
has  increased  the  number  of  tank  corrosions  by  making 
the  water  clearer,  thus  facilitating  the  galvanic  action. 

Iron-bearing  waters  are  often  very  annoying  to  the 
householder.  By  precipitation  of  iron  oxide  they  may 
render  the  water  turbid,  make  stains  of  iron-rust  on 
clothes,  choke  up  the  pipes,  tanks,  etc.,  and  form 
brown  stains  in  marble  wash-bowls  under  the  faucets. 


68  The  Value   of  Pure  Water 


Use  of  Hard  Water  in  the  Industries 

In  almost  every  instance  where  chemical  manufac- 
turing processes  involve  the  use  of  water  its  hardness 
affects  the  result.  The  effect  may  be  an  economic  one 
and  cause  merely  a  waste  of  material,  but  it  may  be  a 
vital  one  and  influence  the  entire  process.  As  illustra- 
tions, the  operations  of  bleaching  and  dyeing,  tanning, 
sugar-refining,  and  paper-making  may  be  mentioned. 

Dyeing  is  a  process  which  involves  many  very  delicate 
reactions  and  in  which  immense  quantities  of  water  are 
used  in  mixing  the  colors  and  in  washing  the  goods. 
In  dyeing  silk,  for  instance,  1,000  gallons  of  water  are 
sometimes  used  for  each  pound  of  silk.  Many  aniline 
colors  dissolve  badly  in  calcareous  waters.  The  colors 
of  cochineal,  methyl  blue,  etc.,  are  materially  altered 
by  the  presence  of  hardening  constituents,  and,  as  hard 
waters  often  fluctuate  in  hardness,  the  matching  of 
delicate  colors  is  a  matter  of  difficulty.  In  madder- 
dyeing  hard  waters  may  not  only  cause  changes  of 
shade,  but  may  cause  precipitates  to  form  in  spots  on 
the  goods.  In  wool-dyeing  the  effect  of  hard  waters  is 
noticeable.  The  fibres  do  not  become  well  degreased, 
and  insoluble  calcareous  soaps  deposit  on  the  threads, 
so  that  they  do  not  take  the  dye  evenly.  Ferruginous 


Use  of  Hard  Water  in  the  Industries    69 

waters  are,  of  course,  highly  objectionable,  especially  in 
white  dyeing  or  bleaching. 

Great  quantities  of  water  are  used  in  tanning.  The 
unhairing  of  the  skin  is  done  by  loosening  the  roots  of 
the  hair  by  saponifying  with  quicklime  the  greasy 
matter  secreted  by  the  small  hair-glands.  If  the  water 
contains  a  large  amount  of  calcium  carbonate,  some  of 
this  is  precipitated  on  the  dermal  tissue.  This  deposit 
interferes  with  the  absorption  of  the  tannin  in  the 
cells  of  the  hide  and  causes  brown  stains  to  appear  on 
the  leather. 

Sugar-refining  requires  pure  water.  It  is  used  in 
filtering  the  syrups  through  animal  charcoal.  This 
charcoal  has  the  power  of  absorbing  the  hardening 
constituents  of  water,  and  if  it  does  this  to  a  consider- 
able extent  it  quickly  loses  its  bleaching  power,  which 
has  to  be  restored  by  treatment  with  dilute  hydro- 
chloric acid.  In  manufacturing  beet-root  sugar  the 
phenomenon  of  osmosis  comes  into  play  between  the 
water  and  the  juice  of  the  beet-root,  the  cell-walls  play- 
ing the  part  of  a  dialyzer.  Hard  waters  are  harmful 
in  this  operation,  as  they  tend  to  cause  an  appreciable 
amount  of  sugar  to  be  retained  in  the  mother-liquor. 
The  lower  the  salts  in  solution  the  easier  it  is  to  elim- 
inate the  saline  matter  from  the  molasses  and  increase 
the  yield  of  sugar. 


7° 


The  Value  of  Pure  Water 


Hard  water  is  unsuited  for  paper-making  for  several 
reasons.  It  interferes  with  the  sizing  used  on  the 
paper  and  has  an  important  effect  on  dyeing,  as  men- 
tioned above.  Iron  salts  especially  are  objectionable 
in  a  paper-mill.  Under  the  influence  of  an  alkali  the 
iron  is  precipitated  on  the  paper,  giving  rise  to  brown 
spots  and  streaks.  Hardness  affects  the  process  of 
paper-making  in  another  way.  The  paper-pulp  is 
carried  over  two  sheets  of  wire  gauze,  and  if  lime  is  pres- 
ent in  the  water  the  pores  of  the  wire  gauze  are  likely 
to  become  choked  up  with  what  is  called  "water  stone," 
which  is  really  nothing  else  than  calcium  carbonate. 

Many  other  industries  might  be  mentioned  in  which 
hard  waters  play  an  important  part,  such,  for  instance, 
as  the  manufacture  of  soap,  wool-scouring,  printing, 
brewing  and  distilling,  photography,  ice-making,  etc. 
It  would  be  interesting  if  some  industrial  chemist  would 
take  up  this  matter  and  furnish  the  data  now  lacking, 
to  show,  in  dollars  and  cents,  the  effect  which  hard 
water  has  on  these  various  manufacturing  processes. 

Use  of  Hard  Water  in  Steam-making 

Steam  users  suffer  more  from  the  bad  effects  of  hard 
waters  than  any  one  else,  consequently  the  use  of  hard 
water  in  boilers  requires  more  than  a  passing  notice. 


Use  of  Hard  Water  in  Steam-making    71 

The  economical  operation  of  a  boiler  demands  good 
water  as  much  as  it  does  good  coal.  This  is  better 
appreciated  to-day  than  it  was  a  few  years  ago.  With 
the  older  boilers  of  small  size  and  simple  type,  the 
character  of  the  water  was  of  less  importance,  but  the 
present-day  striving  for  economy  in  steam  production, 
which  has  resulted  in  the  use  of  so  many  auxiliary 
attachments  to  the  modern  boiler,  requires  that  great 
care  shall  be  given  to  the  quality  of  the  water  used. 
Bad  boiler  waters  may  cause  corrosion,  scale,  foaming, 
overheating,  and  leaks.  These  result  in  loss  of  heat, 
in  increased  labor  of  attendance,  in  greater  expenses 
for  operation  and  repairs,  in  a  shortened  life  of  the  plant, 
and  in  increased  liability  of  explosion. 

All  natural  waters  are  more  or  less  corrosive  on  ac- 
count of  the  presence  of  dissolved  oxygen  and  carbonic 
acid,  but  waters  which  contain  chlorides,  nitrates,  sul- 
phates, etc.,  may,  under  certain  conditions,  become  very 
corrosive.  Swampy  waters  and  some  driven  well- 
waters  usually  contain  more  free  carbonic  acid  than 
ordinary  river-waters.  In  some  of  the  mining  districts 
the  only  waters  available  are  distinctly  acid  and  are 
exceedingly  corrosive.  Magnesium  chloride  is  corro- 
sive, and  that  is  largely  why  sea-water  is  so  objection- 
able for  use  in  boilers.  It  is  often  said  that  sodium 
chloride  is  not  corrosive,  but  in  the  presence  of  silica 


72  The  Value  of  Pure  Water 

it  may  become  so.  Waters  which  are  naturally  only 
slightly  corrosive  may  become  very  corrosive  if  allowed 
to  concentrate  in  the  boiler,  and  this  they  will  do  unless 
the  boiler  is  occasionally  emptied  and  cleaned.  Corro- 
sion is  increased  by  mechanical  action — that  is,  by 
movements  of  the  boiler-sheet  caused  by  expansion  and 
contraction.  It  is  most  likely  to  occur  at  points  where 
there  is  a  tendency  to  movement  and  also  along  the 
water  line.  Local  corrosion  is  frequently  referred  to  as 
"  pitting"  or  "  grooving."  Occasionally  galvanic  action 
may  cause  corrosion. 

The  formation  of  boiler  scale  is  due  to  the  precipita- 
tion from  the  water  of  the  carbonates  and  sulphates  of 
calcium  and  magnesium  together  with  smaller  amounts 
of  other  salts  and  of  suspended  matter.  For  each  salt 
there  are  certain  conditions  which  will  cause  precipita- 
tion. Calcium  carbonate  is  quite  insoluble  after  its 
extra  molecule  of  carbonic  acid  has  been  driven  off  by 
heat.  Calcium  sulphate  becomes  almost  insoluble  above 
250°  F.  (i2o°C.).  Magnesium  carbonate  is  changed  to 
magnesium  hydrate  and  precipitated.  Boiler  scale  may 
also  contain  compounds  of  iron,  silica,  alumina,  organic 
matter,  etc.,  in  endless  variety  of  composition.  Gener- 
ally speaking,  carbonate  scales  are  soft  and  are  more  in 
the  nature  of  a  sludge  or  mud  than  true  scale.  Sul- 
phates, on  the  other  hand,  form  a  hard  scale,  especially 


Use  of  Hard  Water  in  Steam-making    73 

when  mixed  with  magnesia  and  silica.  Calcium  sul- 
phate precipitates  in  a  compact  crystalline  form,  which 
can  sometimes  be  removed  only  by  hammering  and 
chipping.  It  may  happen  that  different  kinds  of 
scales  occur  in  the  same  boiler,  due  to  the  different  tem- 
peratures of  the  sheet  in  different  parts  and  to  the  cir- 
culation of  the  water.  The  scale  in  the  tubes  is  often 
different  from  that  on  the  sheets. 

Hard  waters  invariably  form  scale  and  comparatively 
soft  waters  may  also  do  so  if  the  boiler  is  used  too  long 
without  being  emptied.  Concentrated  soft  waters  are 
almost  as  bad  in  their  effects  as  waters  naturally  hard. 
The  greater  the  hardness,  however,  the  more  trouble- 
some will  the  water  be. 

Foaming  is  caused  chiefly  by  an  excess  of  alkaline 
salts,  which  cause  the  water  to  form  suds  as  if  soap  had 
been  added.  This  makes  a  boiler  unmanageable  and 
affects  the  quality  of  the  steam. 

If  grease  is  present  in  the  water,  the  sludge  or  scale 
may  become  very  sticky.  In  this  condition  it  adheres 
tenaciously  to  the  plates  and  causes  overheating  which 
usually  occurs  in  spots.  Scales  themselves  may  cause 
the  sheets  to  become  overheated.  They  may  also  give 
rise  to  unnatural  movements  of  the  shell  through  ex- 
pansion and  contraction,  and  may  thus  ultimately 
cause  leaks. 


74  The  Value  of  Pure  Water 


Financial  Loss  from  Use  of  Hard  Boiler  Waters 

Many  estimates  have  been  made  to  show  how  much 
the  steam-maker  loses  by  using  a  hard  water  instead  of 
one  satisfactory  in  character.  Figures  are  often  given 
showing  the  effect  of  boiler  scales  of  different  thickness 
on  the  loss  of  fuel.  For  example,  it  is  sometimes  stated 
that  a  boiler  scale  one-eighth  inch  thick  will  cause  a 
loss  of  20  per  cent  in  the  heat  utilized  from  the  fuel, 
while  a  scale  three-eighths  of  an  inch  thick  will  cause  a 
loss  of  50  per  cent.  It  is  said  that  the  resistance  of 
sulphate  scale  to  the  passage  of  heat  is  from  twenty  to 
fifty  times  as  great  as  that  of  an  equal  thickness  of 
wrought  iron,  and  that  a  film  of  grease  one  one-hundredth 
of  an  inch  thick  is  equivalent  in  its  heat-resisting  powers 
to  a  boiler  scale  one-tenth  of  an  inch  thick,  or  to  a  steel 
plate  ten  inches  thick.  Figures  of  this  character  can- 
not be  considered  as  very  accurate,  as  they  are  based  on 
insufficient  data,  yet  they  serve  to  illustrate  the  fact  that 
boiler  scales  do  cause  very  material  losses  of  heat.  Other 
figures  have  been  given  to  show  the  reduced  life  of  boilers 
by  reason  of  corrosion  or  the  presence  of  scale,  and, 
while  too  inaccurate  to  deserve  quotation,  they  help  to 
illustrate  the  same  truth,  that  bad  boiler  waters  cost 
money  to  the  steam  user. 


Loss  from  Use  of  Hard  Boiler  Waters    75 

The  most  accurate  figures  perhaps,  showing  the  ex- 
cessive cost  of  hard  waters  as  compared  with  soft  waters, 
are  those  which  have  been  compiled  by  some  of  the 
Western  railroads.  They  are  based  upon  data  relating 
to  the  use  of  water  in  locomotives  before  and  after  the 
installation  of  water-softening  plants.  The  following 
table,  based  on  a  report  of  the  Chicago  and  North- 
western Railway,  is  an  excellent  illustration  of  this: 


TABLE  19. 

COMPARISON  SHOWING  THE  EFFECT  OF  WATER-SOFTENING  AT  SEVEN- 
TEEN STATIONS  ON  THE  CHICAGO  AND  NORTHWESTERN  RAIL- 

ROAD. 

(The  two  years  represent  the  condition  before  and  after  softening.)" 

1902  1903 

Ton-mileage,  in  million  ton-miles 2934  3154 

Increase  in  ton-mileage 230  (7.5%) 

Pounds  of  coal  per  100  ton-miles 28 . 7          27 . 5 

Saving  in  coal,  pounds  per  100  ton-miles 1.2 

Saving  in  coal  (at  $3  per  ton  for  3,000  mil- 
lion ton-miles) , . . .  $30,000 

Average  assignment  of  engines  (83%  of  them 

were  in  constant  service  both  years) 159  154 

Saving  in  assignment    f  engines 5 

Saving  in  engines  (!(  %  interest  and  depre- 
ciation on  cost  of  five  engines  at  $10,000 
each) $5,000 


76  The  Value  of  Pure  Water 

Number  of  boiler-makers  employed 36  23 

Number  of  helpers  employed 42  30 

Total  number  of  laborers  on  boilers 78  58 

Saving  in  laborers 20  (26%) 

Saving  in  wages  of  boiler-makers  and  helpers $7,700 

Saving  in  materials  for  boiler-repairs Not  estimated,  but 

known  to  be  large 

Boiler  failures  from  leaky  flues 544  99 

Boiler  failures  from  leaky  fire-boxes 33  20 

Boiler  failures  from  leaky  arch-tubes 6  1 

Total 583  120 

Reduction  in  number  of  boiler  failures 463  (79%) 

Estimated  saving  to  the  road,  all  causes $75,000 

The  figures  show  a  decided  saving  in  coal,  in  labor,  and 
materials  for  repairs  on  engines,  etc.  One  of  the  most 
important  advantages  to  the  road  was  the  decrease  in 
the  number  of  engine  failures.  This  means  more  to  a 
railroad  man  than  to  an  outsider,  as  it  involves  losses 
due  to  the  stopping  of  many  trains,  the  derangement  of 
time-tables,  charges  for  perishable  freight,  overtime, 
etc.  The  Committee  on  Water  Service  of  the  American 
Railway  Engineering  and  Maintenance  of  Way  Asso- 
ciation summed  up  the  benefits  of  the  use  of  soft  water 
to  the  railroads  as  follows: 

1.  Fewer  boiler  failures  due  to  leaks. 

2.  Longer  life  of  flues  and  fire-box  sheets. 

3.  Reduced  cost  of  labor  for  repairs  and  washing 
boilers. 


Loss  from  Use  of  Hard  Boiler  Waters   77 

4.  Increased  locomotive  mileage  between  stoppings. 

5.  Increased  ton-mileage  per  pound  of  coal  consumed. 

6.  Decreased  number  of  locomotives  in  service. 

7.  Better  feeling  among  the  men  due  to  fewer  failures 
and  shorter  time  of  the  road. 

8.  Less  expense  in  cost  of  overtime  and  delayed  time. 


INDEX 


A 

PAGE 

Esthetic  deficiency  of  water 20-24 

diagram  for  calculating 18 

Esthetic  rating  of  water 17-24 

Albany,  N.  Y.,  reduction  in  death-rates • 10 

value  of  supply  increased  by  filtration 12-44 

Anabaena 5 

Analyses,  interpretation  of 60 

Application  of  formulas 35 

Attractiveness,  determinations  which  relate  to 16 

qualities  affecting  consumer 6 

B 

Bacterial  examinations  necessary.    59 

Befouled  water 56 

Binghamton,  N.  Y.,  value  of  supply  increased  by  filtration 43 

Boiler -scale 72 

Boiler,  foaming 73 

Boilers,  effect  of  hard  water  upon •jl 

financial  loss  from  use  of  hard  water  in 74 

C 

Camden,  N.  J.,  typhoid  rate 14 

Chlorinated  waters,  effect  upon  plumbing 67 

79 


8o  Index 

PA  OB 

Color 17-20 

effect  of 37 

objection  to 21 

Contaminated  water 56 

Contamination,  effect  of 36 

Corrosion  of  boilers  due  to  hard  water 72 

Cost  of  filtration. 48 

D 

Death-rates,  reduction  in 10-1  r 

Depreciation,  due  to  inferior  quality 5-6 

formulae  for  calculating 30 

Diagram  for  calculating  the  aesthetic  deficiency  of  water 18 

Disadvantages  of  hard  water 62 

Diseases  transmitted  by  water. g 

Distilled  water,  amount  paid  for 22 

Dyeing,  effect  of  hard  waters  in 60 

Dysentery g 

E 

Epithets  applicable  to  natural  waters 55 

Epithets  applicable  to  waters  with  substances  artificially  admixed.  56 

F 

Filtered  water 37 

Filtration,  cost  of .  . 48 

Financial  loss  from  use  of  hard  boiler-waters 74 

Foaming  of  boilers 73 

Formulae,  application  of 35 

summary  of  . 30 

Fuertes,  Jas.  H.,  typhoid  death-rates !5 

G 

Ground-water,  temperature  of 29 

Ground-waters,  depreciation  of 37 


Index  8 1 

H 

PAGE 

Hard  water,  definition  of 63 

disadvantages  of 62 

effects  of 64 

effect  of,  in  dyeing 68 

effect  of,  in  household 63 

taste  of 65 

use  in  industries 68 

use  of,  in  steam-making 70 

Hardness 4-6 

amount  of  soap  necessary  to  soften  water 26 

cost  of  soap  because  of 26-27 

effect  of 41 

experiments  with  soap 25 

standards  of 24 

Hazen,  Allen,  cost  of  nitration 48 

reduction  in  death-rate n 

House  filters  used .  22 


I 

Ice  used  to  cool  water 28 

Impregnated  water 56 

Infected  water 57 

Iron 4-29 

Iron-bearing  waters,  effect  of 67 


L 

Lawrence,  Mass.,  value  of  supply  increased  by  nitration 42 

Leighton,  M.  O.,  value  of  human  life 7 

Life,  value  of 7-0, 

N 
New  York  City,  depreciation  of  water-supply 39 


82  Index 

o 

PAGE 

Oberlin,  value  of  water-softening 47 

Odor 17-20-39 

effect  of 37 

quality  of 21 

objection  to 21 

P 

Paper-making,  use  of  hard  water  in 70 

Physical  quality 45 

Pittsburgh,  typhoid-fever  death-rate 36 

Poisoned  water 57 

Polluted  water 56 

Pure  water 2 

meaning  of 3 

difficulty  in  defining 4 

has  a  financial  value 5°~53 

Purification,  value  as  insurance.  . 45 

Putrid  water 55 

Q 
Qualities  affecting  consumer 6 

S 

St.  Louis,  depreciation  due  to  turbidity 39 

Sanitary  quality 6-42 

represented  by  typhoid 7 

Soap 25 

amount  necessary  to  soften  water 26 

cost  of,  because  of  hardness 26-27 

experiments  with,  on  hardness 25 

Soiled  water 55 

Spring-water,  amount  paid  for 22 

amount  used 23 


Index  83 


PAGE 

Springfield,  Mass.,  depreciation  due  to  odor  and  turbidity 39 

Stained  water 55 

Steam,  use  of  hard  water  in  making 70 

Sugar -refining,  effect  of  hard  water  in 69 

Summary  of  principal  formulae 30 

Surface-waters,  depreciation  of 37 


T 

Tainted  water 55 

Tanning,  effect  of  hard  water  upon 69 

Temperature,  affects  consumer 7 

depreciation  due  to 29 

ice  used 28 

objection  to  high 28 

of  ground-water 29 

of  surface-water 29 

Troy,  N.  Y.,  death-rate I0 

Turbidity 17-19-20-39 

effect  of 37 

Typhoid 3_5_7_g_9 

average  death-rate  decreasing 36 

Camden,  N.  J Z4 

death-rates  in  cities rg 

death-rates  in  twelve  cities !6 

financial  loss  from  each  death 12 

loss  in  dollars  per  million  gallons  by 13 

"normal" I2 

percentage  mortality 8 

Pittsburgh 36 

Pittsburgh,  loss  due  to 37 

"residual" I2 

tendency  toward  increase  from  north  to  south 14 

transmitted  by  milk,  etc I2 

Washington,  D.  C I4 


84  Index 

w 

PAGE 

Water,  diagram  for  calculating  the  aesthetic  deficiency  of 18 

Water  analyses,  interpretation  of 60 

Water-softening,  value  of 47 

Washington,  D.  C,  typhoid-fever  death-rate 14 

Watertown,  N.  Y.,  depreciation  of  supply  because  of  color 39 

value  of  supply  increased  by  filtration 43 

"What  is  pure  and  wholesome  water ?" 53 

Whipple,  M.  C.,  experiments  on  taste  sensitiveness 65 

Wholesome  water 2 

meaning  of 3 

difficulty  in  defining 4 

has  a  financial  value 5°~53 

Winnipeg,  value  of  water-softening  at 47 


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